The super-slow conversion of the U.S. to metric (2025)

https://www.thefabricator.com/thefabricator/blog/testingmeasuring/the-super-slow-conversion-of-the-us-to-metric

by itvision • 6 months ago

136 404 6 months ago

jxdxbx4• 6 months ago

The metric systems's worse flaw was doubling down on base 10 instead of the plainly superior base 12.

c048• 6 months ago

Only in certain fields. For most interactions divide by 10 is far easier than divide by 12, and you'd end up with far, far more "eyeballed" measurements.

So no, as a human being, I'm fine with base 10.

rob74• 6 months ago

Or you'd have to go all in and write numbers in base 12 too, then dividing by 12 would be easier...

p-e-w• 6 months ago

Being able to count using fingers is more valuable than having one more prime factor.

jabl2• 6 months ago

You can actually count to 12 on your fingers using one hand. Use the thumb as a pointer, then for each of your other fingers you have three joints. So 3*4=12.

jabl2• 6 months ago

As long as we count in base 10, it makes sense for the unit system to also be based on base 10.

As for changing the world to counting in base 12, yes there would be some advantages, but really, good luck with that.

pornel• 6 months ago

Too bad there are 11 players on the pitch, otherwise US could switch entirely to the football fields measurement system.

kalleboo• 6 months ago

The right time to fix that mistake wasn't in metric, it was while creating our numbering system.

atoav• 6 months ago

Consider marking it with /s next time.

tom_• 6 months ago

This can make sense for currency, but units of weight and distance and so on are infinitely divisible. You can just have a third of a metre if you like. Or 333 mm if the inaccuracy is acceptable. And so on.

wongarsu• 6 months ago

And it's not like 1 is some special value. If you start from a base of 120cm you get enough even divisions that you rarely run into the need for fractions

fainpul• 6 months ago

Obviously base 60 is superior to all

https://www.youtube.com/watch?v=R9m2jck1f90

nayuki12• 6 months ago

Possibly yes. But every implementation of base-60 I've ever seen is actually implemented as alternating base-6 and base-10.

A true base-60 would have 60 unique symbols for the different digital values, much like how in our set of ten digits {0123456789}, none of the symbols have any rhyme or pattern with respect to the others.

Good luck memorizing the ~1800 entries of the base-60 multiplication table.

unglaublich• 6 months ago

Lol sure, in no A0 years!

kstenerud• 6 months ago

The metric system is the tool of the devil! My car gets 40 rods to the hogshead and that's the way I likes it!

bluGill8• 6 months ago

Someone else must be paying for your fuel. Nobody who pays for their own fuel likes that.

duskdozer• 6 months ago

Base 12? That's a small number. Now base 13? 13's a big number. The biggest number, perhaps. That's what they're saying at least. Base 13, 13 colonies, now that's America.

thomasmg• 6 months ago

The PDF standard uses base 85 encoding (Ascii 85).

vidarh• 6 months ago

Unless everyone worked in base 12 numbers too, that'd be a mess. Part of the beauty of metric is how often calculations devolve to shifting the decimal point.

Ekaros2• 6 months ago

And nothing really prevents metric system from working in base-12. Ofc base 12 kilometre would be larger than base-10. But it still would work.

Base 10 really is used because our number system is base 10. And more so base 1000. Apart from some cultures.

altern82• 6 months ago

Isn't base 10 easier because you just add/remove zeros, and also we have 10 fingers to count..?

bluGill8• 6 months ago

No, converting units is not a useful exercise. airplanes are measured in mm - even the full length is in mm not decameters or even hecameters (i had to look those prefixes up, spellcheck doesn't even know the word, but I think they are correct)

nayuki12• 6 months ago

I hope you're comfortable with changing literally every number in society to base 12. My house cost $42A765_12. My SSN is 399-AA-5866 and phone number is (289) 257-B84A. The distance to the moon is actually 50A693_12 feet. I used the additional symbols A and B as per usual notation, but it's okay if society agrees on some other symbols for the extra two digit values.

If you don't make the base of the number system agree with the base used for converting between units, then conversion becomes so much harder. For example, it's not immediately apparent that 204 inches is 17 feet, but it is immediately apparent that 204 cm is 2.04 m. Furthermore, when the base disagrees with conversion factors, you run into issues like variable-length fields - like, "2ft 9in", "2ft 10in" (notice the inches transitions from one digit to two digits).

jxdxbx4• 6 months ago

Yes I am literally a member of the dozenal society

cjs_ac• 6 months ago

U.S. customary (the more accurate name for what’s sometimes the called the British Imperial system)

For those wondering why there is this distinction, the British Imperial units were created by the Weights and Measures Act 1824; US customary units follow the Winchester Standard of 1588.

pjc50• 6 months ago

And in a few places they're different (US measuring "cup" vs UK, US gallon, etc)

edit: ref https://www.bbc.co.uk/bitesize/articles/zfnjb7h

beardyw2• 6 months ago

UK doesn't use cups in recipes and fuel is dispensed in litres.

Road signs are still in miles.

ch_123• 6 months ago

As someone who generally uses metric units, but grew up around English Imperial units - if an American says that a person weighs a certain number of pounds, I need to convert to stone and pounds in my head in order to get a meaningful mental model of how much that person weighs.

cupofjoakim• 6 months ago

The US being stuck in imperial is such a meme nowadays with "freedum units" and the like. It's yet another odd thing that makes it easy for the rest of the world to laugh at the US. In these isolationist times I doubt this will change soon though, but it'd definitely help international collaboration.

yurishimo• 6 months ago

Everyone who wants to collaborate internationally is already doing it. Science in the US is entirely metric. Construction and domestic measurements are the two biggest holdouts and honestly they’re both negligible. Given the proliferation of global manufacturing, most businesses are converting at the end before retail for US customers.

If the government was competent, they could rip off the bandaid and everyone would adapt within a year or two, but we need to wait at least 3 years for that to even begin to become a possibility again.

mgoetzke• 6 months ago

The fact that canadian lumber companies seem to be switching their machinery to metric is funny though. https://woodcentral.com.au/canadas-sawmills-weigh-metric-swi...

neutronicus• 6 months ago

Construction is negligible?

I guess you imagine we’ll all be calling half inch pipe twelve seven after this year adjustment period?

I guess people do it with bullet calibers.

kevin_thibedeau• 6 months ago

The US has gone almost fully metric on plywood thickness due to globalization.

FridayoLeary• 6 months ago

They got rid of the penny. Just suggest that the Imperial system is some leftist conspiracy and they'll have moved over by the end of the month.

t-33• 6 months ago

Honestly, I don't think anyone would raise much of a fuss over changing distance measurements to metric. Both centimeters and inches are easy enough to eyeball or rule-of-thumb, meters and yards are basically the same, and larger units are only relevant for speed limits and travel planning. Metric lacks a good "foot", but I guess people would get used to eyeballing things in ~50cm increments instead.

Weights are even easier as pretty much everyone uses grams as the smallest daily unit and most people can convert to and from metric on the fly for ounces, lbs, kgs. Liters aren't uncommon, and ml<->gram equivalence for water is well-known. Traditional kitchen volumes probably wouldn't be displaced because metric has no answer for those in first place.

Temperature is where metric will fail to gain adoption because Celsius totally sucks unless your daily life consists only of boiling or freezing water at sea level. No advantages over Fahrenheit except maybe arguably for science, because it's Kelvin with an offset.

cucumber37328424• 6 months ago

The unit itself doesn't actually matter. Even industries with the least precision set their stuff up with so much precision that the unit you use basically doesn't matter.

Your machine may spit out widgets that are plus or minus an inch. But when you set up the machine you set it up to the 1/16 regardless. Swapping all that to metric doesn't actually change anything other than the number the guy setting it up dials it in to.

walthamstow2• 6 months ago

re construction, we use 8x4ft sheets of timber in Britain still, same as before, we just call them twelve-twenty-by-two-four-forty now.

deadbabe• 6 months ago

Most likely the current administration will pass executive orders banning the use of metric system, and then force other countries to switch to imperial or face heavy tariffs.

zahlman4• 6 months ago

Jokes of this form were tired by about November 5, 2024.

ecommerceguy3• 6 months ago

Aren't imperial units considerably easier to calculate on the fly in construction and when squaring? They seem to come more natural for me.

NuclearPM• 6 months ago

No. They are only more natural to you because you are used to it.

ecommerceguy3• 6 months ago

Have you never used a tape measure before? How about a speed square? Yes easy comes natural for me. I like that.

pineappleoreos• 6 months ago

When one of familiar with something, it always feels more natural.

Ronsenshi• 6 months ago

Can you give an example? I can't imagine calculating conversions between inches and feet to be easier than using millimeters/centimeters/meters. Or using mostly millimeters in construction in Europe. You have one unit to deal with that generally tends to be integer value. No need to fractions.

bluGill8• 6 months ago

You don't convert. Airplanes are designed in mm and you never need meters. Houses are in inches - we say 92 5/8. Or sometimes 2 feet 3 inches. Our measurement tools have both marks so we can do it without coversion.

ecommerceguy3• 6 months ago

Imperial’s base-12 (inches) is more factor-rich than base-10:

12 divides cleanly by 2, 3, 4, 6

10 divides cleanly only by 2 and 5

Obviously downvoters who've never used a speed square nor tape measure before.

bluGill8• 6 months ago

Depends. they are designed so the whole units are easy for the common things you do with that size. this is a common case for things will still do today like we did 200 years ago (like build houses). But even in those areas a lot of things are not round units.

When things are not nice round units though both systems are equally hard. This is common in the modern world where we do a lot of things impossible 200 years ago.

in reality you almost never calculate on the job. You measure what is on the print and anything not on the print is figured out 'when you get there' by measuring the space left when you get there - which also corrects for previous measurement errors

taeric• 6 months ago

Related to this, I find the "default to round numbers" influence interesting on things like minimal speeds. Where my understanding is many metric based systems have a smallest max speed of 30km/h. Which is between the common 15 and 20 that I'm used to seeing as the lowest.

I tried asking on a forum once on how this impacted default room sizes. I see standard ceiling size in the US is moving to 9 feet. I am assuming places on metric would not standardize on that number, but curious if they would just stick to the nearest half, or go to the nearest whole meter. (I "tried" asking, as people seemed to think that you would just design the room to be 2.74 meters and call it a day. That strikes me as very unlikely, as design tools really love "snap to grid.")

gdwatson• 6 months ago

Units based on base 12 or base 2, as U.S. standard measures tend to be, are easier to divide in many ways.

Now if we used base 12 numbers instead of base 10, and we had a system of units based on that, I bet we’d have the best of both worlds. No idea if Napoleon could have imposed base 12 arithmetic on most of Europe the way he did metric, though.

sarchertech10• 6 months ago

The problem is that Fahrenheit is a bit more convenient for describing the weather. Inches and feet are a bit more convenient for measuring human scale things and for being easily divisible by more numbers. And we’re used to the rest of it.

Unless someone comes along and forces it on you, for the average person, there’s not enough incentive to switch.

plaguna• 6 months ago

"Fahrenheit is a bit more convenient for describing the weather" - you might need to show us an example here that is not biased. Because to me, Celsius is a bit more convenient for describing the weather.

bluGill8• 6 months ago

It is what you are used to for both of you. you could make your own measurement system and it would work fine once you get used to it - until you need to communicate with someone else who isn't used to it.

sarchertech10• 6 months ago

On the Fahrenheit scale, the majority of daily temperatures in the vast majority of the US fall between 0 and 100, which is -17 and 37 Celsius, and it’s more granular without introducing a decimal point.

bryanlarsen2• 6 months ago

Not as laughable as "metric is more convenient for human scale things". "Human scale things" includes fractions of an inch and fractions of a mile, which are horrible in customary units, and includes both the foot and yard which are used confusingly interchangeably. Metric is far superior for human scale measurements.

And that's only length. It gets worse outside of length. Like WTF is an ounce?

its_ethan• 6 months ago

0 degrees F is a cold winter day, 100 degrees F is a hot summer day

0 degrees C is a cold winter day, 100 degrees C means you're dead

I think he's suggesting that a 0-100 scale for temperature/"relative warmth outside" is more intuitive than a 0-37 scale. It's easier to to place 73 degrees on a 0-100 relative warmth scale than it is to place 18 degrees on a 0-37 scale (unless of course you grew up calibrated to the 0-37 scale and know that 18degrees means you maybe need a light jacket or whatever).

I think it's funny that one of the main benefits of metric is its base-10-ness where things scale so nicely from 1-10-100-1000 etc. but then for temperature we're supposed to be fine with a 0-37? Fahrenheit is basically the 1-100 version of temperature (when it comes to weather).

stronglikedan• 6 months ago

Celsius isn't granular enough for describing how humans feel temperature.

MarkusWandel5• 6 months ago

Oddly enough as a person born in a metric country, now living in Canada which is metric, and always educated in metric, I agree with you on the feet and inches. "A couple of inches" doesn't imply nearly the precision that "5 centimeters" (using the US spelling on purpose) implies. Similarly my own height of 5'10 is much more "human scale" than the 178cm that it says on my passport.

Not for engineering though!!! Being able to add 1/64 and 5/16 and 17/32 etc. in your head without stumbling is a skill that I did not acquire.

Don't agree on the Fahrenheit though and for the same reason! Degrees are just the right scale, and besides, anchored at freezing (0) and typical boiling (100) points. But that's just habits. Probably if I'd grown up with Fahrenheit, I'd prefer it too. And besides the oven defaulted to Fahrenheit and we never changed it. 350F...

bluebarbet• 6 months ago

And I would come the opposite conclusion to you.

On Fahrenheit, the Americans are surely right. For describing the weather, a system where the usual range is 30-100 is clearly more useful than one where it's 0-37, because you can say "high 70s" instead of the weirdly specific "about 27", and "low 40s" instead of the awkward "around 5 to 7".

I say this as a European who has never used Fahrenheit.

jventura• 6 months ago

As someone born and living in a country that uses the metric system, I do not understand a bit of what inches and feets mean. Tell me something has 10-15 cm, and I know what it means. I measure 173cm, I know what one meter is about. 5'10? What the hell is that?! 5 feet and 10 inches? Some people have small feet, some have larger. And what is an "inch"? :)

Oh, and fahrenheit, what the hell it means? 0ºC means ice, 100ºC means boiling water, 40º feels summer around here..

I guess I'm saying that you understand the values of the imperial system because you're used to them, as I'm used to values in the metric system..

sarchertech10• 6 months ago

That’s not what I’m saying at all. I’m saying that a system where the majority of air temperatures in the vast majority of the country fall between 0 and 100 is slightly more convenient than one in which they fall between -17 and 37. 0 is really cold it doesn’t frequently get colder than that in most of the country. 100 is really hot, in most places it doesn’t get hotter than that.

Feet are slightly more convent for declining human sized things because meters are just a little too big to describe human height and centimeters are a bit you

If you were designing a system to describe humans with no other consideration you’d probably pick one where 10 units was the average human height. And feet is closer to that than meters. Also you can divide 12 by 6 and 3.

I’m not saying that customary is superior just that it does has certain advantages.

SideburnsOfDoom6• 6 months ago

Inches and feet are a bit more convenient for measuring human scale things

nope, this is mere familiarity. You find it more natural because you're more used to it, nothing more.

There is nothing convenient about a system where "below zero" and "below freezing" are not synonyms. Or at least that's how I find it. because of what I'm used to. But at least I realise that might be a fact about me, not a fact about the world.

sarchertech10• 6 months ago

I replied to you above for temperature but for human scale measurement, if you were to design a system for human scale measurement from scratch, you’d likely make 10 units equal to the average height (you could also argue for making 1 unit equal to that).

Feet are closer to that ideal than meters. That’s all that I meant. Also 12 inches is divisible by 3 and 6. And if you get into fractions of an inch, you always stick with powers of 2 which makes some math easier. Some math so much easier in metric.

The more important factor is obviously familiarity. Both systems clearly work. But neither is inherently superior in all applications.

prmoustache• 6 months ago

funny related video from Loic Suberville.

https://www.youtube.com/shorts/XiEM57ifX54

alkonaut2• 6 months ago

Having converted science, manufacturing etc, what's the first (or next) true consumer facing thing that could change?

mschild• 6 months ago

Grocery sizes. In fact, a lot of them already have it on the items. Typically because a lot of products are also sold in Canada so they put the ml measurement next to the gallons.

alkonaut2• 6 months ago

Yeah is fl.oz on consumer containers _really_ seen as a volume measurement, i.e. thought of in terms of conversion "How many of these to a gallon", "what does a 6-pack weigh" and so on?

Or are they more like t-shirt sizes "I know I want a 16oz can to drink and I know how big they are"?

amanaplanacanal5• 6 months ago

When I go to buy liquor it seems to already be mostly in metric, sizes are 500ml, 750ml, and liter.

nayuki12• 6 months ago

If I understand correctly, the FPLA ( https://en.wikipedia.org/wiki/Fair_Packaging_and_Labeling_Ac... ) requires grocery items to be labeled in both American units and metric units. Metric-only is illegal in America but legal and common in Canada. I have shopped in American and Canadian supermarkets and speak from personal observations.

It seems the exception is that wine imported into the US can keep metric-only labeling, so I have indeed seen bottles labeled only "750 mL", sold in the US.

qingcharles4• 6 months ago

Mexico too. Anyone immigrated from basically anywhere is more used to buying in metric. And some products have already made the conversion, e.g. soda bottles.

tzs5• 6 months ago

An interesting case on grocery items is that solid things that you pour (breakfast cereal, flour, sugar, salt, for example) the nutrition label gives the serving size in a US customary volume measure and in a metric mass measure.

For example my breakfast cereal label says a serving is 1 cup or 45g.

Liquids seem to give a US customary volume and a metric volume. For example the milk I put on that cereal says a serving is 1 cup or 240mL.

Checking some sauces I have on hand thick liquids (ketchup and sriracha) are US volume and metric mass like pourable solids and thin liquids (like soy sauce) are both US and metric volume like milk.

Butter is also US volume and metric mass.

A little bit of research says that this is actually regulatory. For things where how much you can fit in a given volume varies quite a bit depending on how you pack it the FDA requires that the metric units on the label be mass units, and that nutritional information is for that amount of mass of the thing.

The actual amount of flour in a cup of flour for example can vary quite a bit depending on how much air got in when you poured it. If the label says it is 110 calories for 1/4 cup (30g) and you want to actually use 440 calories of flour in something you should measure out 120g rather than 1 cup.

For things like milk 1 cup is going to have the same amount of milk no matter how you pour it, so they use volume measurement for both customary and metric.

sevensor• 6 months ago

manufacturing

This is sadly far from the truth. Manufacturing is nowhere near metric conversion. Horsepower, foot-pounds, and my all time least favorite unit, the mil, are everywhere. And relatedly, manufacturing execution systems that use localtime internally cause all manner of hilarity twice a year. It’s like we’re just deliberately trying to be bad at measuring things.

ghaff3• 6 months ago

Force and mass is what always drove me crazy in engineering school. I assume that courses in the US have largely given up trying to pay some lip service to common older units but sorting out pounds-mass, pounds-force, and slugs? Pretty sure I couldn't do it today.

fluorinerocket• 6 months ago

The rocket company I worked at designed their orbital rocket in inches and lbm. Engine flow rates in lbm/s, temperatures in deg Rankine, thrust in lbf. Btu/hour/inch^2/degR heat transfer coefficients.

altern82• 6 months ago

Why change? Imperial was Washington's dream, after all... https://www.youtube.com/watch?v=JYqfVE-fykk

threemux2• 6 months ago

I'd part with cups and teaspoons/tablespoons and the like, but you'll pry inches/feet/yards and fahrenheit from my cold, dead hands. They're both more convenient for daily use. I think I'd prefer to keep miles as well but I don't have a good reason for that one.

Fahrenheit has more precision without using decimals for the thing 99% of people are using temperature measurements for: air temp. Where I live, we generally experience 5 degrees F - 100 degrees F at different points of the year. That's 95 degrees of precision with no decimal. In C, that's -15 to 37.8, a mere 52.8 degrees. The difference between 75 (usually a beautiful day) and 85 (hot) is 23.8C to 29.4C. Everything packed into this tight range.

Inches/feet being base 12 divides better into thirds and fourths, which is very useful in construction.

For science, sure, I'll use metric.

Tor3• 6 months ago

What's the problem with decimals? They're all numbers. -4.5 degrees C is fine, isn't it? (The actual temperature right here right now). Where's the problem?

gonzalohm3• 6 months ago

You don't even need decimals. 45x10^-1. There, fixed

sfn42• 6 months ago

You don't even need decimals. Nobody who uses celsius gives a shit about the decimals. It's -4 or it's -5 and even that distinction is irrelevant.

Unless you're doing some kind of scientific calculaton there's no need to think about decimals of celsius at all. Just like Fahrenheit users surely don't care whether it's 50 or 53 or whatever. It's around 50, that's all you need to know.

jlongman• 6 months ago

That’s funny because when I work with Fahrenheit I just work with 5°F ranges to compensate for the approximate mental math required. Eg very quick mentally, 100°F = 37.778 °C (thanks autocorrect) = (100-32)/2 = 34.

But if it was closer to freezing say 42°F =5.556 °C (again) so 5°C. So arbitrarily we could say 57°F was 12°C =53.6 °F actually.

But a true Canuck knows knowing the temp is barely half the battle, what’s the wind speed and humidity? 29°C can be a lovely day if it’s dry or completely unbearable if it’s humid.

We hardly ever use decimals for weather-related measurements, the other factors above being more relevant.

Contrast that with measurements where I would say if you need to know a precise one you should be using decimal; ie what do you do if it doesn’t precisely third or fourth? If you’re talking about tool sizes then any system works as long as your froodle matches the grommlet.

candiddevmike• 6 months ago

(F - 30) / 2 = ~C

C * 2 + 30 = ~F

modo_mario3• 6 months ago

Everything packed into this tight range.

AS someone that grew up with metric that feels fairly natural and not tight at all?

Inches/feet being base 12 divides better into thirds and fourths, which is very useful in construction.

I used ruler tapes with both metric and imperial on either side and i always wondered how one could use the inches since they're so big and didn't always have the same minute subdivisions. Also doing my math in decimals seemed easier than calculating with quarter or 1/8th inches or smaller.

For science, sure, I'll use metric.

Surely it would feel more natural to use the same for everything and all measurements.

I want to know how much rainwater my IBC roughly holds. I take out my measuring tape real quick. I'm not even sure how I'd get started in imperial without some strong intuition build up over years?

svara• 6 months ago

(...) grew up with (...) feels fairly natural (...)

Really all there is to that discussion.

threemux2• 6 months ago

I mean it's mathematically a tighter range. I think part of this comes down to the more mild and less variable European climate. There is just less emphasis on air temperature so you don't see the drawbacks.

Your tape measure didn't have 1/3, 1/4, 1/8, 1/16, and 1/32 subdivisions? Sounds like a bad tape measure (or really just one where US Customary was an afterthought).

As for science, well, most people don't do it. Those that do can use different things in different contexts, it's not that hard.

flohofwoe• 6 months ago

They're both more convenient for daily use.

That's really just because you're used to it. The rest is rationalization...

OTH of course the rest of the world can hardly complain since we didn't switch time or (angle-)degrees to decimal either ;)

etiennebausson• 6 months ago

Not switching to metric for time is reasonable, because there are already two existing 'natural' units for time (the day and the year), and they don't align on each other in metric (a year of exactly 1000 days would be so much easier, but we'll have to deal with reality as it is... or accelerate the rotation speed of the planet I suppose).

So long as we live on earth, metric time won't make much sense.

qingcharles4• 6 months ago

Right. It's like when countries switched to the Euro or decimalized. There's a period when everything feels really janky and everyone complains and then a couple of years later everything is just fine and they forget what the old system was even like.

insane_dreamer4• 6 months ago

The French did try to switch time to decimal after the Revolution. It was probably the most hated change they made by the local population, and didn't last long.

The problem was that it messed with the week, having a "day of worship / rest" every 7 days, which was then every 10 days

Kim_Bruning5• 6 months ago

An eyeballed yard is roughly the same as an eyeballed meter. An eyeballed foot is 1/3 of that. You can stick 4 inches in 10 cm roughly.

And I just poke my nose out the window and look outside to see what the temperature is

  Freezing.... ~30°F.... ~0°C

  Need coat... ~50°F... ~10°C

  T-shirt..... ~70°F... ~20°C

  Melting..... ~90°F... ~30°C

Rules of thumb can be learned either direction!

ps HN tables are not really a thing, are they?

pps Suspiciously many experiments are conducted at 293K

cucumber37328424• 6 months ago

What you're ignoring is that a hundred plus or minus is a good range for average humans to grapple with and Fahrenheit splits the temperature swings in a given region across an approximately 100deg range.

So using Fahrenheit results in a pretty decent "as high as it can be without being clumsy" measurement system that covers just about all earthly temperatures.

If we only cared about increments of five or so degrees you could go higher resolution and it'd be fine because rounding would occur like we do with vehicle speeds. Or we could go lower resolution and just make the degrees bigger, which is basically what celsius is.

samus10• 6 months ago

The difference between a yard and a meter adds up quickly. Already a 25 yard swimming pool yields significantly different times to cross it than a 25 meter one.

gonzalohm3• 6 months ago

Interesting. As an European living in the US. The only US units that I find useful are cups, teaspoons and tablespoons. And that's only for cooking. It's way faster to measure volume than weight (although less accurate)

kakacik2• 6 months ago

Those are not US measures, we use them in Europe as well

consp2• 6 months ago

It used to be based on relative size, so if you have a set of spoons and cups and use the same for all measurements they are ballpark right for your recipe (and some minor difference accounting for user error). These day's it's defined anyway in both metric and imperial. As soon as you start weighing something from the recipe it goes out of the window as that defines the rest of the relative measurements. For that reason I really dislike the recipes telling you to measure teaspoons of spices but grams or ounces of flour. I don't have two sets of measurement cups available. These days most cooking sites mention both though.

On a sidenote: an ounce is 100g here and a pound 500g. Mainly by being in common usage and translated to common used weights. "An ounce more okay?" is an easy way to sell more without mentioning how much it actually is in numbers.

Symbiote3• 6 months ago

In some European countries, it's common for rough recipes to use decilitres, e.g. 2dL of flour.

1 US cup is 2.37dL.

Otherwise, a metric tablespoon is 15mL and a teaspoon is 5mL.

ddellacosta2• 6 months ago

As a pretty experienced American home baker I don't understand how you can assert that it's faster to measure volume with cups or etc. than to put a bowl on a scale and simply pour stuff in, measuring everything in grams. It's not even close in terms of speed, convenience, _and_ accuracy.

jeppester• 6 months ago

I like this!

I wonder if there's a place on the internet where I can find more of this sort of seemingly strong and well-thought out arguments for something that is so clearly subjective (if not just inferior).

cucumber37328424• 6 months ago

seemingly strong and well-thought out arguments for something that is so clearly subjective

Any platform where snooty articulate people congregate will have such arguments by the bushel.

nayuki12• 6 months ago

https://www.reddit.com/r/Metric/

eddyg• 6 months ago

Fahrenheit forever!

    0°C.................100°C
    Cold                 Dead

    0°F.................100°F
    Really Cold    Really Hot

btbuilder• 6 months ago

0C = Frozen!

evil-olive3• 6 months ago

I see this argument repeated every single time someone tries to defend Fahrenheit.

if "room temperature" was smack in the middle, at 50 degF, you might have a point.

but no, it's pure post-hoc rationalization.

being naked at 0 degF will kill you. being naked at 100 degF will (usually) not. they're not remotely equivalent.

instead, think of it this way - human beings are mostly water, and 0 to 100 degC is "percentage of the way from water's freezing point to boiling point".

room temperature is "about 20% of the way to boiling". 40% or higher starts to cause our bodies to overheat. a typical sauna will be somewhere between 50 and 70% of the way.

Polizeiposaune• 6 months ago

Don't forget:

  0K..................100K
  Dead          Still Dead

relaxing5• 6 months ago

You don’t need to worry about taking up room for a decimal place when your outdoor temperature is only ever 2 digits at most.

gordonhart2• 6 months ago

Miles didn't click for me until I learned that it's defined by how far you'll travel in 1,000 paces (where a pace is an L+R step). Now I find it very useful to convert steps<>distance traveled, which is actually quite useful if you walk a lot!

zzzoom• 6 months ago

You'd have to be quite tall to average an ~80cm step. 193cm (6'4") according to a quick search.

d--b• 6 months ago

Can you at least switch to 1/10th of inches? The 1/4th, 1/8th, 1/16th is very annoying

convolvatron• 6 months ago

we do. being a machinist in the US means being able to convert between decimal inches, mm, fractional inches, and things like feet all the time. not to mention other completely arbitrary units like sheet gauge, fastener number and inverse thread spacing. there are also decimal feet for carpenters.

this for me is the real appeal of metric, not that somehow a meter is magical, but at least there is one system, with a consistent set of rules, that allows us to do some magic things like tell the approximate volume of water given a weight.

edit: omg I forgot about nominal wood sizes. the underlying system actually has different units based on the material and the usage. copper gauge is not the same as steel gauge. thats pretty hopeless. for precious metals we also have the pennyweight

AngryData5• 6 months ago

That would be negating 90% of the usefulness of using a fractional system though. It is barely a step up from using a prime number like 7 or 11 as a number base or divisor.

AlotOfReading2• 6 months ago

Even in construction, feet/inches/yards kinda sucks. 1:10 scale drawings are painful to do manually, division by 2 is a bit erratic, and bolt sizing is a horrible mess. Metric bolts are nice and consistent.

With you on temperature though.

briffle• 6 months ago

My wife was a surveyor in a past carreer. We have a tape measure in the garage that measures to the nearest hundredth of a foot. It is just so weird to see. Forcing decimal on a measurement that does not normally have it just makes me uncomfortable.

https://surveysupplyinc.com/lufkin-12-foot-hi-viz-engineers-...

TheCoelacanth• 6 months ago

The extra precision is fake.

They might have measured precisely at the weather station, but local variation in temperature makes that extra precision meaningless unless you are located exactly where the measurement happened.

Even in a climate controlled room, there will be a degree or two of variation between different parts of the room.

evil-olive3• 6 months ago

for another example of this: a lot of people "know" that the average human body temperature is 98.6 degF.

that extra decimal point gives people false confidence about the measurement being more precise than it is.

because so much science (even in the US) happens using the metric system, the actual measured average [0] is 37 degC, and 37.0 degC == 98.6 degF. the nuance of the average being more of a confidence interval (37 +/- 0.5 degC, possibly larger) gets lost as well.

0: https://en.wikipedia.org/wiki/Human_body_temperature

rickydroll2• 6 months ago

If you want to get even more divisive, try converting people to metric baking measurements. Baking bread and cakes is much more repeatable if you use mass rather than volume to measure ingredients.

The results from this recipe were never consistent when I used volume measurements. I converted to mass in metric and now I get consistent results.

adapted from: [https://www.justsotasty.com/wprm_print/11594](https://www.justsotasty.com/wprm_print/11594)

Banana Brownies

Prep Time: 15 minutes mins

Cook Time: 35 minutes mins

Total Time: 50 minutes mins

### Equipment

- 9x13 inch (23 x 33 cm) baking pan*

### Ingredients

- 227 g unsalted butter (2 US sticks) unsalted butter (The better the butter, the better the results. In the U.S. market, Kerrygold yields the best results, followed by Cabot, and "well, it's still brownies" Market Basket house brand.) - 400 g dark brown sugar - 2 large eggs - 5-10 ml vanilla extract - 150 g mashed bananas (about 2-3 large, brown bananas) - 156 g all-purpose flour (I prefer King Arthur All Purpose Unbleached Flour) - 60-70 g cocoa powder - 2-3g teaspoon salt - 280(ish) g chocolate chips (I prefer Ghirardelli Bittersweet 60% Cacao Baking Chips, use 1 bag) )

### Instructions

- Preheat the oven to 350F degrees (180C or 170C fan forced). Line a 9x13 inch (23x33 cm) pan with parchment paper or aluminum foil leaving an overhang around the sides. Alternatively, lightly grease the pan. - Melt the butter in a double boiler. Add in the brown sugar, stir, and let it sit in the double boiler, stirring occasionally until the mixture has a nice caramelly flavor. - While the butter-sugar mixture is cooking in the double boiler, combine the dry ingredients. - Sometimes cocoa powder is lumpy, and you may need to sift it. The alternative I use is combined flour, cocoa powder, and salt, and use a whisk to mix it all together and break up any lumps if there are any. - Take the brown sugar butter mixture off of the double boiler and mix in the mashed bananas and vanilla. - The bananas usually cool the mixture enough that the eggs won't cook when you put them in, but if the mixture is hot, add some flour, add some of the dry ingredients, and that will cool it down enough to add the eggs safely. - Stir in the chocolate chips. - Pour/spoon the batter into the prepared pan and bake for about 35 minutes, or until an inserted toothpick comes out clean or with a few damp crumbs. - Cool fully (about 4 hours), then slice. Store brownies in an airtight container in the fridge for up to 4 days. (Never last that long in my house)

bigstrat20035• 6 months ago

I use volume measurements for baking and I get consistent results all the time. Perhaps your recipe is especially gnarly, but that isn't true of all recipes.

childintime2• 6 months ago

Nobody I know speaks of temperatures in decimals of Celsius, like no one.

humodz• 6 months ago

The difference between 75 (usually a beautiful day) and 85 (hot) is 23.8C to 29.4C.

If you convert a nice, round number from one system to the other, you'll end up with a more precise, less nice number, which will give the impression that Celsius is harder to use.

In reality, people from metric countries just think in 5-degree increments: 25 is a beautiful day, 30 is hot. It doesn't feel any harder to read than Fahrenheit.

I wonder if there are people that moved to the U.S., switched to Fahrenheit and now find it more intuitive than Celsius. If one is easier than the other, I assume it still doesn't make up for the hurdle of learning a new system.

rkomorn2• 6 months ago

I wonder if there are people that moved to the U.S., switched to Fahrenheit and now find it more intuitive than Celsius.

I've done the move twice in each direction. Neither is more intuitive.

When I moved back to C after 22 years in F, I had to adjust again. It took a few months. The other times were after fewer years, but still took (re)adjusting.

vablings3• 6 months ago

The UK uses miles and miles per (UK) gallon. We talk in feet, inchs lbs and stone for weight. But when it comes to engineering works it is ALL now in metric aside from the older builder, all of my schoolwork was in metric, and we never dealt with the hellish conversions it was all SI units, and we just had to know maybe one or two magic constants in physics and chemistry (molar and something else to do with joules in bond enthalpy)

I worked as an engineer and the only drawings specified in imperial were pre 1970s and all the CNC controls are programed in mm feed rates in mm/rev or mm/min

evil-olive3• 6 months ago

Inches/feet being base 12 divides better into thirds and fourths, which is very useful in construction.

all of the math normal people use in everyday life happens in base 10.

"it's easy because it's base 12" is an absolutely ludicrous idea.

what's 7'5" divided by 3? divided by 4?

what happens if you need to divide by 5?

and sure, there are various mental math tricks you can learn to make this easier...or you could just use the metric system.

7'5" is 226cm. that's a normal, boring, everyday, base 10 integer.

you don't need to learn a special set of "mental math for base 12" tricks. instead you can re-use the same mental math tricks you use for every other base 10 number.

insane_dreamer4• 6 months ago

inches/feet/yards ... more convenient for daily use

only because that is what you are accustomed to

because I grew up with metric, m/cm are much more convenient for daily use

I will allow that a "foot" is useful as an approximate intermediary unit between m and cm

Inches/feet being base 12 divides better into thirds and fourths, which is very useful in construction.

again only because the US construction industry grew up using fractions instead of decimals

bigger_cheese• 6 months ago

I've lived with deg C my whole life it is what I'm used to, the way I experience weather is in 5 degree increments - I live on East Coast of Australia. My Internal rule of thumb is:

Below 10 deg C - it is cold, Heavy jacket weather

10-15 Typical winter weather (at least where I live) light jacket

15-20 Spring/Autumn weather long sleeves no jacket required

20-25 Pleasant day T-shirt weather

25-30 Getting hot, ceiling fans/AC time

30-35 Hot

35+ very Hot

johnnyanmac3• 6 months ago

Fahrenheit has more precision without using decimals

Meanwhile, I'm fine at 98.6 degrees, but everyone freaks out over 100 degrees. it's a more precise unit, right?

feet/inches make more sense to be attached to. they are based on your body parts (roughly), and we spend a lot of time looking at humans. inches divide our fingers, feet are... well, feet. And yards are steps. We intuitively know what all those feel like through everyday life compared to the scientific way we derive a centimeter. inches and feet being base 12 is more a coincidence than anything else (or maybe not. Maybe there's some golden ratio shenanigans at play).

hk1337• 6 months ago

Seems like the U.S. uses metric for most of the important areas and just lets everyone continue to use imperial, whatever they want everywhere else.

JKCalhoun3• 6 months ago

"Back when I was a Catholic-school kid in northern Wisconsin, my school lessons briefly focused on the metric system. This was in the late 1970s."

Man, the progressive school (Comanche Elementary in Overland Park, Kansas!) must have had a huge impact on my life. In addition to open classrooms (I was in Unit 5, not 4th Grade), team teaching, a focus on experimental science, a circular layout to the school with a sunken (architecturally) library in the center…

Yeah, we went over the Metric System that whole year. I can still sing the "Metric Family" song from the film on metric units ("Kilo", "Milli", etc.). And to my young and impressionable mind, the U.S. was joining the rest of the "Free World" in a kind of Star-Trek-like casting aside of the old things that divided us—joining each other with a focus on progress, science, space…

President Carter came along around the same time or shortly after. And I have a photo of a family road trip to South Dakota, Montana: the sign that indicates the altitude of a particular mountain pass has both feet and meters. I Google-mapped the same location recently and of course it's no longer in meters.

I feel like in my elementary school days (the 1970's) the U.S. was on the cusp of a future of optimism—no doubt buoyed by having put astronauts on the Moon, but I was wildly on board for it.

But then some kind of shit seemingly started to poison the country. I don't feel we have ever returned to that level of national optimism. Perhaps 1976, the Bicentennial, was the end of it. (Recently watching the film "Nashville" brought me back a bit of the vibe of the times.)

I've been missing it my entire life since.

ericmay11• 6 months ago

Yeah, we went over the Metric System that whole year. I can still sing the "Metric Family" song from the film on metric units ("Kilo", "Milli", etc.). And to my young an impressionable mind, the U.S. was joining the rest of the world "Free World" in a kind of Star-Trek-like casting aside of the old things that divided us—joining each other with a focus on progress, science, space…

I’ve always found this peculiar because at times I have felt the same, but reflecting over the years and I guess as my mind settling on lived experience and opinions I’ve come to appreciate the Imperial system far more precisely because of its absurdities but also because of its history and usefulness without instrument.

As someone who, well, finds say Renaissance or Impressionist art to so far be the peak of human artistry, I find the imperial system fits in better with that warmth of humanity in contrast to Frank Lloyd Wright, Banksy, minimalism, and the cold calculation of the more “scientific” metric system.

Underneath that all is also this view that the United States at least needs to “join the world” and adopt Metric, and soccer, and such and I find myself increasingly rejecting both and other similar notions in favor of cultural uniqueness and fun over conformity.

I hope we never change sustems, and I don’t think we will anytime soon. If we do, however, we should not switch to Celsius because the useful scale of Fahrenheit is far superior 0-100 versus 0-32. Celsius isn’t very Metric-y.

shoxidizer3• 6 months ago

Frank Llyod Wright lacking warmth and humanity? Never been to Falling Water?

sandbach• 6 months ago

Banksy??

technothrasher• 6 months ago

the useful scale of Fahrenheit is far superior 0-100 versus 0-32.

Well, first of all, I'm not sure why you're defining those scales as the "useful" ones. They don't even equate to each other. But why are you arbitrarily using 100 as the end of your Fahrenheit scale? Just so you can declare it 'Metric-y'? If you read his paper, Fahrenheit's scale is actually 0-96.

nayuki12• 6 months ago

I find the imperial system fits in better with that warmth of humanity

Right, so you enjoy warmth such as: 1 foot = 12 inches, 1 stone = 14 pounds, 1 pound = 16 ounces. Lots of useless names and numbers to memorize compared to kilo = 1000, milli = 0.001.

in favor of cultural uniqueness and fun over conformity

You're writing in impeccable English. As we know, English is an international language and most definitely not the pinnacle of cultural uniqueness or non-conformity. Why not adopt a more esoteric and fun language for yourself such as, who knows, Esperanto, Lojban, Klingon, etc.?

in contrast to [...] the cold calculation of the more “scientific” metric system

Decimals are optimized for cold calculation, yes. Would you like to use a monetary system based on pounds, shillings, and pence - like the UK and Australia right into the 20th century? Did you know that the New York Stock Exchange traded in increments of $1/8 and later $1/16, before fully decimalizing?

jhoechtl2• 6 months ago

So do your marh then in the roman system and have fun with it.

Enjoy the warmth!

klaff• 6 months ago

As a hardware engineer I've been primarily using metric for over three decades, and like the machinist quoted in the article have had to deal with bullshit of converting back and forth. It's not just about inches and centimeters.

If you're working with small motors, the Ke (back-EMF constant) and Kt (torque constant) have different and crazy Reagan units (e.g. V/krpm, inch-ounces/A) but in SI they have units of V/(rd/s) and N-m/A, which if you crunch them down to kg, m, etc. are identical and so have the same numerical value (because they represent the same transformation from electric to mechanical or vice-versa). Power is the product of voltage and current or torque and speed - if you use the SI units no conversion required. Inertia was confusing as hell, some vendors specified it in MOISS, or milli-ounce-inches-seconds-squared, not only involving different unit but you can also get balled up in the mass vs force confusions.

Converting a drawing from one system to the other perfectly is practically impossible. Conversions can't always be exact and because tolerances are commonly specified in round numbers within a system.

In my garage I still have both metric and Reagan-unit tools. Even though my cars, even the American ones have been metric since the '80s, I have to have the other tools for other household things like the garage doors!

And then there's the tire size abomination - an unholy union - a 255R70-14 is 255 mm wide at the bulge, the sidewall height is 70% of that, and the rim diameter is 14 inches.

I agree that 1 °C is too big a step when dealing with thermostats but that's easily solved by using 0.5 °C resolution.

jackvalentine• 6 months ago

I think you’re confusing warmth and use-ability with familiarity.

Nobody who grew up using the metric system feels it ‘cold’ and yearns for something with more character.

MarsIronPI• 6 months ago

I hope we never change sustems, and I don’t think we will anytime soon. If we do, however, we should not switch to Celsius because the useful scale of Fahrenheit is far superior 0-100 versus 0-32. Celsius isn’t very Metric-y.

Except that Fahrenheit's extra precision doesn't really matter. Unless you can tell the difference between 72°F and 73°F, or 34°F and 33°F.

master_crab2• 6 months ago

It was there again in the 90s after the wall fell. Fukuyama was boldly proclaiming the “end of history.” Newt started to kick at the edges with his combative policies but the inertia continued until the dotcom crash and 9/11 came along, and fully ended with the Great Recession.*

* (From my viewpoint as a millennial. Gen Z might think the golden years were during Obama, or just pre-COVID. To some extent every generation has a point in time that they see with rose tinted lenses.)

anonymars• 6 months ago

The Daily Show did a segment on this. I can't find the clip but the title was "Even Better Than the Real Thing" and it was with John Oliver. Anyway the conclusion was "the good old days when life was simpler" are inevitably "when you were a child" -- it would be interesting to see how that holds up with others

antisthenes• 6 months ago

(From my viewpoint as a millennial. Gen Z might think the golden years were during Obama, or just pre-COVID. To some extent every generation has a point in time that they see with rose tinted lenses.)

Of course they do. It's the formative years & youth. Roughly from the time you form a mature consciousness (12-14 yo) to roughly your late 20s or maybe early 30s when all your tastes, preferences etc. are formed.

wffurr3• 6 months ago

> It was there again in the 90s after the wall fell.

Don't forget that connecting everyone to the internet was going to produce world peace, utopia, universal education and understanding. Instead of creating a conduit for memetic viruses to infect the world at unprecedented speed.

MisterTea• 6 months ago

I've been missing it my entire life since.

Childhood Zeitgeist is a perfect term for this. We all pine for it.

FeloniousHam• 6 months ago

I understand existing-tool-holder opposition to a new measurement system, but sweet mother I hate fraction math.

mindslight• 6 months ago

I keep trying to make myself think in terms of 32nds. For example think of a 9/16 wrench as "18", the 1/2 wrench is just "16", and so on. It's a slow process. I want to standardize on some color code for easy cross-brand identification of wrench sizes too, but I haven't come up with a compelling scheme.

The worst is the hardware. I inherited a full assortment of #2-#10 stainless SAE UNC hardware from a business move (already in nice parts drawers, too). It was pretty awesome for just having whatever I needed on hand to build things. But now as I maintain more and more things that are metric native, I've been building up the assortment of metric threads as well.

I suspect this is one of the real pain points of fabricators (plus taps/dies). And I'm guessing they're still still Imperial native due to existing tooling, making the conversions not clean (it's easy to convert 1/2 inch to 12.7mm and measure that, but it's not straightforward to convert 10mm to 0.3937 inches (25.2/64ths) and measure that.

AngryData5• 6 months ago

Im the other way around and think fractional math isn't used enough because it is so easy and useful. I think fractional maths biggest obstacle is everyone trying to avoid it and not learning it in contexts and methods where it excels.

That said, I still use tons of decimal math because sometimes it is more useful, but not always.

yencabulator3• 6 months ago

Even the existing-tool-holder is a weak excuse. My socket wrench set came with two near-identical sequences of wrenches, metric and imperial. I regularly the encounter metric variants in the US. Switching to metric, like the rest of the world, would make things simpler.

jhoechtl2• 6 months ago

I think it was Reagan turning all backwards orientated

wffurr3• 6 months ago

> But then [post-1970s] some kind of shit seemingly started to poison the country.

https://wtfhappenedin1971.com/ - the oil ran out and the post-war boom ended.

nine_k3• 6 months ago

You mean, cheap oil ran out. Also, the last remaining sort-of-gold-standard was abolished, so the money printer could go brrr without much restrain, as needed.

JKCalhoun3• 6 months ago

If you think being tethered to gold was a good thing I wonder if you also believe wealth is a zero-sum proposal? I would think that the explosive growth of wealth since 1971 would cause most to rethink that.

quesera• 6 months ago

The US Metric Board was cancelled in 1982 by one Ronald Wilson Reagan (anagram: Insane Anglo Warlord).

RWR and the charismatic traditionalism he espoused have caused a great deal of harm to American society.

Metrication is not at the top of that list, but it is one of many examples that we still live with today.

ahmeneeroe-v24• 6 months ago

no doubt buoyed by having put astronauts on the Moon

NASA did this using customary units

I've been missing it my entire life since

Surely you've learned by now that you're missing childhood, not an actual thing about the US? I'm asking this as someone who does think this era was peak Americana, but for totally different reasons than you present, and having not been alive then myself.

pezezin2• 6 months ago

NASA did this using customary units

The Apollo Guidance Computer performed all internal calculations in SI units, and only converted to US customary units for display:

https://ukma.org.uk/why-metric/myths/metric-internationally/...

mturmon2• 6 months ago

Katherine Carpenter Elementary, OP, KS for me, in the same era -- just a couple miles from your school.

I share some of the same disappointment, especially going back and noticing disinvestment in the schools, which were one of the gems of the area.

JKCalhoun3• 6 months ago

Shawnee Mission was a gem of the Midwest. I was told that only California had better schools (whosaidthat?).

(And then of course Prop 13 came along and impaled California.)

Kim_Bruning5• 6 months ago

An argument can be made that we should blame Pirates of the Carribean for the fact that the USA is not metric. O:-)

https://www.nist.gov/blogs/taking-measure/pirates-caribbean-...

bryanrasmussen• 6 months ago

I read once that all the educational materials produced to help people move from the old system to metric would cover 3 football fields and weigh more than 28 elephants, so it's nice to see it starting to have some effect.

baggy_trough2• 6 months ago

Hopefully some future president will mandate that the federal government use metric, like Trump getting rid of the penny. The rest of society will gradually come along.

IAmBroom3• 6 months ago

Carter literally did this. Society did not come along.

baggy_trough2• 6 months ago

The feds gave up too early.

yareally• 6 months ago

Honestly, the best way to cook is with grams. Throw everything into the same pot on a scale and keep zeroing it out. Way less mess to clean up. All the top baking recipes tend to already be in grams, but there's plenty of others out there that are not

Also a great use for LLMs. I'll tell it to convert recipes from volume to grams by estimating density. It's surprisingly accurate

walthamstow2• 6 months ago

You can keep your fahrenheit, your feet and your gallons, for all I care, but one thing I will never abide is bolts and nuts and drill bits coming in fractions of an inch.

consp2• 6 months ago

Everybody still loses the 10mm socket anyway, even in the US.

frankus2• 6 months ago

There's now a product for that: https://www.lowes.com/pd/Kobalt-1-4-in-to-1-2-in-Drive-Metri...

zokier3• 6 months ago

Fractions of inch are still tolerable. But just having "#X" drills and screws is pretty silly. 7/32" might need some mental arithmetic, but #6 is just unknowable.

vondur• 6 months ago

It’s a bit odd in the U.S. because we use a mix of units, largely due to industries that combine metric and imperial systems. Most people are familiar with metric volume since so many drinks are sold in 1 and 2 liter bottles, and medications are typically measured in milligrams. Lengths and weights are more of a mixed bag. Many track and field events use metric units now, though longer distances are still measured in miles. Temperatures are still Fahrenheit, which I tend to prefer because the smaller increments give a more nuanced sense of change. I’m comfortable with the metric system since I was a chemistry major in college and a mountain biker, where measurements like suspension travel are usually given in millimeters.

webnrrd2k• 6 months ago

Speaking of mixed units, don't forget the alwys fun distinction of avoirdupois pound vs troy pound...

People sometimes ask "what's heavier, a pound of feathers or a pound of gold?", the implication is that you're stupid for for asking a dumb question. The technically correct answer is that the pound of feathers is heavier. The expected answer is usually that they're the same weight, because there is no difference in weight between the two things that both weigh a pound. The problem is that, in the USA, a pound of feathers is measured with the avoirdupois pound, while a pound of gold is measured in troy pounds. The troy pound is lighter than the avoirdupois pound, so the answer is that a pound of feathers is heavier.

While a troy ounce is heavier than the avoirdupois ounce, and the grain unit is equal in both. So, depending on whether you ask for a pound/ounce/grain, the answer can change. https://en.wikipedia.org/wiki/Troy_weight

samus10• 6 months ago

The smaller increments of Fahrenheit don't matter outside of a chemistry lab.

pengaru• 6 months ago

It will never cease to drive me batty every time I try find a metric fastener for an automotive purpose at a local hardware store.

There are many reasons I can find for leaving the US, but engaging in DIY projects utilizing local suppliers are what's come closest to pushing me over the edge. Especially in this post-SEARS hellscape of low quality made in china junk the market's flooded with. Now not only can I never find the fasteners I need, the tools suck too!

qingcharles4• 6 months ago

I used to end up blowing all my money on ordering from Amazon and paying for same-day delivery, which usually means within a couple of hours in big cities.

I'd always waste my time going to Home Depot etc and getting aggravated at their metric fastener selections.

alnwlsn• 6 months ago

They specify dimensions in feet, inches, and fractions of an inch. But not all of them do.

There are many more fun and exciting non-metric measurements you might encounter than plain old fractional inches.

A fabricator might encounter sheet metal thickness in "gauge". Wire sizes, ammunition, and machine screws also come in "gauge" sizes but all four are different scales. US drills come not only in fractional inch sizes, but letters and numbers as well. Furnace efficiency is often specified in percent, but air conditioner efficiency comes in SEER. Water softener capacity is in "grains". Pipe threads come in "inch sizes", but that usually means NPT. Metal hardness and rubber durometer measurements have their own scale which doesn't really belong to either camp.

To be fair, a lot of these are categorical units. Screws come in #2 or #6 or #4, but you'll never need to worry about #3.7.

A wise professor once told me "All these different units will not be going away within your lifetime, so you better get used to working with them."

zahlman4• 6 months ago

Gauges are a measurement, but they aren't a unit. They don't necessarily have any linear correspondence to actual distance/volume/whatever, and in fact are typically inverse (higher number = smaller thing). And yes, they're categorical. (Sometimes you even see 00 as a gauge number.)

zokier3• 6 months ago

Sometimes you even see 00 as a gauge number

or 0000. Which then can conveniently be abbreviated to 4/0.

vablings3• 6 months ago

Metal hardness having a bunch of different units is quite annoying but also interesting.

There are quite a few ways to measure the hardness the most interesting being Vickers. You plunge a diamond of a known force into a surface and measure the size of the indentation. This is surprisingly accurate but does leave a small diamond mark on your surface.

With a sufficiently small part a blacksmith or other folks can determine the hardness of a steel just by listening to how it rings. Hey, you can also test for cracks with a ring test, the most common use is ring-testing a vitrified grinding wheel to see if there is no crack

Alot of engineering is just listen and maybe the odd hit with a hammer

gossamer• 6 months ago

The highway between Tucson and Nogales, Arizona, I-19, is the only highway in the country that has signage only in kilometers. It has been that way since 1980. It was a pilot project for the Metric Conversion Act. The highway is 102 kilometers long (63 miles).

buildsjets• 6 months ago

If you specify all your bolt heads as 19mm and 13mm, then a 3/4" wrench or a 1/2" wrench is usually good enough to get the job done.

Similarly, a 1/4-20 bolt will fit in a M6 tapped hole if you use a large enough hammer.

A hazardous aspect of US threadforms is that #10-32 machine screws and #8-32 machine screws have the same pitch. So you can fit #8 bolts in a #10 hole and sometimes, they FEEL like they made good torque, because they engaged one side of the tapped hole, when they really have no tension capability whatsoever.

Reference the British Airways flight 5390 accident where the pilot got sucked 3/4 the way out the cockpit window and slammed against the side of the fuselage while a flight attendant clung to his feet and the co-pilot safely landed.

Also note that a British designed and built product was using US threadforms...

https://admiralcloudberg.medium.com/the-near-crash-of-britis...

https://en.wikipedia.org/wiki/British_Airways_Flight_5390

tzs5• 6 months ago

Reference the British Airways flight 5390 accident where the pilot got sucked 3/4 the way out the cockpit window and slammed against the side of the fuselage while a flight attendant clung to his feet and the co-pilot safely landed.

That incident led to a major change in how aircraft windows were designed. Instead of being fitted from the outside they were changed to being fitted from the inside.

When fitted from the outside the job of the fasteners is to keep the cabin pressure from blowing the window out when the plane is high up and the outside pressure is low. When the plane is on the ground gravity will keep the window in place and the fastener isn't doing much.

Botch installing the fasteners and you don't find out about until the window blows out at high altitude, like on that flight.

When fitted from the inside the job of the fasteners is to keep the window from falling in due to gravity when the plane is on the ground or at low altitude. At higher altitudes the cabin pressure pushes the window firmly into the frame and the fasteners aren't doing much.

Botch installing the fasteners and the window falls in on the ground or at low altitude which is a lot easier to deal with then a window blowing out at high altitude.

frankus2• 6 months ago

The diabolical case is M5 versus 10-32. About a 4% difference in diameter and about 0.8% difference in thread pitch. Basically indistinguishable with the naked eye and even the "nest the threads in each other" check doesn't help without a pretty long length of threads.

beloch• 6 months ago

To those who cling to customary units because...

1. "They're more intuitive". They're not. You're just familiar with what 70 F feels like. If you're used to metric, 70 F is meaningless, but you intuitively know what 20 C feels like.

2. "Metric leads to lots of awkward numbers." All systems will fortuitously have round numbers in some contexts and awkward numbers in others. Customary units are different in that there are awkward numbers baked into the system. e.g. 5280 feet in a mile. 128 ounces in a gallon.

3. "It's too much trouble to change." You're already using metric units. U.S. customary units have, metrologically, been defined in terms of metric units since the Mendenhall order of 1893[1]. i.e. A meter is defined in terms of how far light can travel in a period of time defined by a hyperfine transition frequency of Caesium. If you needed to know exactly how long a meter is for a very precise measurement, a reference meter could be produced in a lab by aliens who have no idea what a meter is by using this definition. No such definition exists for a foot or yard. Nobody maintains physical reference yards (the old-school method) anymore. If you want those aliens to measure out a yard precisely, you tell them how to measure out a meter and then tell them 1 yard = 0.9144 m.

[1]https://en.wikipedia.org/wiki/Mendenhall_Order

prmph• 6 months ago

Yeah, those people should also think about the fact that even the customary units die-hard do not use micro-feet, milli-feet, or nano-feet, etc.

fragmede4• 6 months ago

A slightly more esoteric Imperial unit is "mils", for thousandths of an inch. 1 mil = 0.001 inch. Which means 1 mil = 25.4 micrometers if we also want to use a non-traditional meter measurement.

bigstrat20035• 6 months ago

You're already using metric units.

No we aren't. It doesn't matter what the units are defined as, that is not what determines which units we are using.

acdha• 6 months ago

In many cases we are, though. A ton of machined things use metric units (and thus need metric tools), and that’s spreading into a lot of other areas like medicine and food packaging. It’s nowhere near absolute but the trend is noticeable.

rconti2• 6 months ago

Counterpoint to #1, celsius increments are too large. I laugh every time I see a thermostat in a car or home that needs to have steps like 20, 20.5, 21, 21.5.. :)

nine_k3• 6 months ago

Do you honestly notice the difference in comfort between 20°C and 20.5°C? I suspect even the heating element is not that precise, let alone the actual room temperature.

They only case in daily practice where 1°C is too large is the difference between normal body temperature (36.5°C) and mild fever (37.0°C), but thermometers have to be graduated in much smaller subdivisions anyway.

scoofy• 6 months ago

I mean, it's arbitrary. I've lived in a Fahrenheit country and a Celsius country and both systems work fine. Resolution issues exist for both systems (you can still benefit from decimals in Fahrenheit for coffee and tea brewing)

I prefer Fahrenheit because it's based around the human, but it really doesn't matter, and it's probably better long term to have measurements that are not based around the human condition, but we're talking about benefits to society tens of thousands of years from now, rather than today.

fragmede4• 6 months ago

How is that a counterpoint to #1? By that same logic, inches are too big an increment so it's hilarious every time fraction of one is used. 15/16ths? lololol!

cogman104• 6 months ago

Temperature is the worst metric unit to pick for this. Both the imperial and metric versions of temperature are completely arbitrary. It's really baffling to me that THIS is the one that most people talking about metric superiority cling to. Where metric shines is when you talk about subunits like mg vs g vs kg. You don't do that with temperature almost ever. So so what if water boils at 212F vs 100C? Pinning 100 at the boiling point of pure water at standard atmospheric pressure is every bit as arbitrary as Fs original 100F pin to the internal body temperature of a horse.

Otherwise I agree with you. I just wish stronger arguments would be made. Measuring distance, speed, weight, volume in metric makes a lot more sense and is more intuitive. It's easy to relate 300mL to 1L. or 1cm to 1m to 1km. And that is where most of the value of metric comes from. The fact that we basically never think in terms of kC or mC is why using temperature is very weak.

mitthrowaway2• 6 months ago

(A standard horse in standard health, of course).

johnnyanmac3• 6 months ago

Pinning 100 at the boiling point of pure water at standard atmospheric pressure is every bit as arbitrary as Fs original 100F pin to the internal body temperature of a horse.

I mean, every unit is arbiturary. But we need to pick something.

I don't have any love for either, but F is the easiest to pick fun at when none of the standard temperatures make any sense. 32 for freezing water, 212 for boiing, 98.6 for human temperature? The 0 and 100 scale were based on the freezing point of some particular saltwater mixture and 90 degrees for human body temperature (which was corrected and then the scale updated to get to the modern temperature).

nine_k3• 6 months ago

"Customary units" are a varied bunch.

The inch-foot-yard-mile scale are not uniform, and not easy to calculate. Their only convenience is easy divisibility by 3. The practical example of uniform scale of this kind is seconds-minutes-hours, which, I suppose, go all the way down to the Sumerian 60-based scale. The mm-cm-m-km are much easier in practice.

Sub-inch units are an honest binary system, and as such is pretty practical. The fact that it's written as a ratio of decimal numbers is sometimes unhelpful though, comparing 7/16" and 1/2" takes either mental gymnastics or memorization. Millimeters are somehow more convenient here, but not by such a large margin as with inch-foot-yard scale.

The Fahrenheit scale is uselessly arbitrary; 0°F does not match anything useful, and 100°F is not that useful either.

The only mile that makes sense is the nautical mile, 1 nm matches 1" of arc on the map / globe, the same way as 1 km is 1/40,000th of the arc.

AngryData5• 6 months ago

0F is useful in areas where they salt roads because thats the temperature many salts stop being effective and previously good road might turn to ice sheets.

But it isn't a good reason all by itself.

psadauskas• 6 months ago

I read a study many years ago, I haven't been able to find it for awhile. It took people who had grown up using each system, and asked them to estimate things just by guessing. For example, "How long is that wall?" or "How far is it from here to the post office?" or "How heavy is this paperweight?". People who'd grown up using customary were significantly more accurate in their guesses.

The study surmised it was because those units had been developed over millennia to be useful at human scales. When eyeballing the length of a wall, centimeters are too granular and meters are to course, but feet are "just right". You might guess a wall is 12 feet long, and be pretty close, but 3 or 4 meters aren't that accurate, and nobody really guesses 3.5 meters.

Same with temperature. 0 - 100°F is about all we as humans will usually experience, so its very convenient when talking about the weather or HVAC thermostats.

They are worse when doing math or conversions, and while that's annoying for scientists and engineers, in most people's everyday lives it comes up so infrequently it doesn't really matter. If something is less than a mile, you don't suddenly convert to feet and do math, you just say "about a half mile".

Personally, I do woodworking (which in the US is always imperial) and 3d-printing (which is always metric), and often combine the two. When doing woodworking or carpentry, its nice that a foot is evenly divisible by 3 or 6, or that half of 3/8ths of an inch is 3/16ths.

asdff• 6 months ago

It makes sense. Curling my finger it is pretty much dead on 1 inch from the tip to the first joint. My foot is a little shorter than 1 foot, but in shoes, pacing it out one foot after another, it is nearly dead on as well. A lot of people measure using anatomy with conventional units.

johnea2• 6 months ago

That sounds like total bullshit to me...

bigstrat20035• 6 months ago

People get bogged down in arguments about what's better or more natural, but in my opinion those always miss the point. The truth is, there's no incentive for the US to switch. If you're a typical adult living in the US, you already know all the conversions you will need (12 inches to a foot, etc etc). The math isn't hard, because you always have a calculator at hand in this age. In short, imperial units have zero downside for most people. On the other hand, switching units of measurement does have a major downside as you have to relearn to estimate everything in the new units. That would be fine if metric was solving a problem for you... but it's not, so why switch?

The only people who benefit from a switch to metric are kids (cause they won't have to learn the imperial conversions). And they, for better or for worse, don't get a say. If people really want the US to switch measurements so badly (which I have no idea why anyone gives a shit what our country does, it's not like it affects them), then they need to come up with an actual compelling benefit to adults in the US if they switch. 100 years ago there was one: you can do conversions more easily. But today there is not, and until one surfaces there's going to be zero pressure to switch units.

upofadown• 6 months ago

“I’m currently working on a mounting plate that’s 4.5 by 8 in. that needs a 40 mm bore 1/2 -in. deep located 75 mm from the edge with m10 tapped holes and two 1/4-20 set screws tangential to the bore. Please kill me.”

When I was designing stuff here in Canada, that was basically Wednesday. One big advantage of the USA withdrawing from trade is that Canada will have the opportunity to finally complete the metric conversion.

dekhn• 6 months ago

I work across both english and metric all the time (CAD, 3d printing, science, woodworking in the US) - I just mentally switched (age 52) to metric first in my head (specifically, I think "that's 10cm" not "that's 4 inches" when I look at something.

Woodworking became a lot more enjoyable- I don't know why- when I started to think "I need to shave off 1mm" instead of "shave off 3/64 inch" or whatever.

watersb2• 6 months ago

My elementary school years in the US really pushed metric units.

And every science class I've ever had was exclusively SI units. Except for Thermodynamics, which sometimes uses BTUs and steam engines.

estimator7292• 6 months ago

We're in such a stupid time. I'm an EE, I typically do all my engineering in millimeters, but most of my coworkers prefer the clownshoes unit "mils". Half our soldering irons are set to Fahrenheit, the others Celsius.

In ordinary every day life, I've found that I use metric for measurements under an inch or under an ounce. At a certain upper limit it makes more sense to use metric for large values too.

So I have to suffer with the magic constant 25.4 bouncing around my brain every day forever and constantly converting trivial measurements into worse units.

I will never convert a measurement to fractional inches. If you must have inches as an input you can suffer a damn decimal point.

jrm44• 6 months ago

Obligatory "what it's based on doesn't matter."

Like programming languages and UIs, it's what and how people use them. Imperial tends to be better because it's more "evolutionary."

timbit422• 6 months ago

Base 10 is more evolutionary because we, and many animals, evolved with 10 digits on our hands and feet.

jrm44• 6 months ago

Yes, and that is why it "won" even though there are pretty good arguments for 8, 12, 16 and so on.

Measuring things is "for humans."

johnea2• 6 months ago

This just reinforces my old saying:

If you want to try to understand why the US is so fucked up, just look at England...

Ylpertnodi• 6 months ago

just look at England.

And perhaps Scotland, Wales, and Northern Ireland, and/ or Great Britain, the British Isles, and/ or the United Kingdom?

Fucked up, indeed.

jiggawatts• 6 months ago

The fish is the last to know it lives in water.

96% of the world’s population and 75% of its nominal (but not PPP adjusted!) GDP is metric.

All science is metric.

Other arguments simply don’t matter. How fine the Fahrenheit vs Celsius scales are or whatever is pointless, irrelevant debate.

Join the rest of us, or slowly fade into irrelevance. There is no third option.

You’re that one mansion with the doddering old cranky fool still lighting their place with town gas while everyone else has been using electric lighting for decades.

The next time the street is dug up, your pipes won’t be reconnected.

“So what if our spaceships occasionally crash into Mars at full speed because we got mixed up with our units… again? We can afford it!” — apologists.

insane_dreamer4• 6 months ago

I don't think the title is accurate.

There is no super-slow "conversion" of the US to metric.

There is a super-slow adoption of metric _alongside_ the "customary" Imperial system.

dragonwriter• 6 months ago

The US Customary system is not the Imperial system. Though they are frequently confused, since they share a bunch of units, and even more names of units with different definitions.

insane_dreamer4• 6 months ago

true, but they're both equally outdated for the purposes of this discussion

mark-r5• 6 months ago

We may get there eventually just as a consequence of being part of the world economy.

I noticed a couple of years back that my "U.S. Customary" wrenches weren't fitting my new plumbing fittings which were definitely not metric, but metric wrenches did. Probably made in China.

Then last summer I noticed something similar with lag bolts. The U.S. Customary socket fit the head, but it was nearly identical to a metric one that fit just a little better. The threads are designed to go into wood, not a nut, so if they were metric you'd never even know.

pfannkuchen• 6 months ago

With most calculation happening via computer these days anyway, do the advantages of the metric system become less relevant?

yegle• 6 months ago

It becomes my habit pointing out the Metric sign on EB 580 when driving my out-of-town friends to the Premium Outlet.

https://www.sfgate.com/travel/article/how-kilometers-appeare...

rstuart4133• 6 months ago

I actively avoid stuff made in the USA, precisely because they don't use metric. For example, you can get a USA bolt with all sorts of threads and dimensions, or you can buy a 100mm M8 that is compatible with every other M8 bolt / nut made in the world. That boils down to bolts made in any country, bar the USA.

Every time the USA manufacturers something that isn't metric, you've made it incompatible with the rest of the world. The USA got away with that when I was young because they were the world manufacturing powerhouse. Now, those powerhouses are based on Asia. They define the units most of the world sees, and they use metric. So if I buy a Chinese mower, all the bolts are metric and I'm guaranteed the local hardware store stocks them.

Time has moved on, the USA is now a follower, not a leader in most things bar digital services. If they want to return to selling those things to the world the speeds have to be in km/hr, weights in kg, sizes in mm or meters, the temperature in Celcius, pressures in Pascal's.

tsoukase• 6 months ago

US system was good for the expansion in Far West 200 years ago. Count steps and thumbs to measure distance and feel the temperature on your skin. Now it has no utility and the US should "surrender" in a democratic fashion to the rest of the world. Of course any definition of a physical constant is valid, like how long I run with one breath right now. But there is already a majority that wins.

yencabulator3• 6 months ago

Pure hell of growing up metric and being forced to use inches is

- what's half of 1-7/8"

Metric: half of 44mm is 22mm. half of 45mm is 23mm [1]. half of 46mm is 23mm. Trivial

- which one is bigger 5/16" or 3/8"

Metric: 9mm is obviously bigger than 8mm.

Fractions are just unnecessarily complicated.

[1] Millimeters are small enough that you'll never need to go below that except in specialties like machining.

The super-slow conversion of the U.S. to metric (2025)

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