11 ms·

Ask HN: Why it is hard for US to move to metric system?

• jb1991 4y ago
  It's hard for any culture to do anything that is deeply ingrained into its habits. Think of all the things that would have to change everywhere, in everything, when something as basic as a unit system changes.
  • derbOac 4y ago
    I was going to write what you just wrote, so I agree. However, I also think to some extent the US is changing, it's just happening very slowly. I think a lot of commerce and travel is part of it. If you buy something designed and produced overseas, and you have to get parts for it, it will be in metric. Lots of imports are in metric, if you travel you deal with metric, and so forth and so on. I've been to US hospitals that only keep charts and communicate in metric as a matter of policy, etc. The only remaining things in the US that are hard for me to intuitively deal with are speed when driving and temperature, and temperature I'm starting to kind of fuzzily intuit.
    • hattmall 4y ago
      Temperature should be easy. Don't try to convert it. Just know that it's based around people instead of water. Anything out of the bounds 0-100 is extreme and to be avoided. Maybe it's just so intuitive having grown up with it, but it just seems to make perfect sense that the numbers are based around how you feel in relation to heat.
      • jb1991 4y ago
        The idea that things are "out of bounds" for "people" up to 100 C is a little strange. Try stepping outside when it's only half that temperature outside, or even just one-third. It's much simpler than that, and has nothing to do with people; it's the range between freezing water and boiling water, and that's it.
        • SketchySeaBeast 4y ago
          I think when they said "Anything out of the bounds 0-100 is extreme and to be avoided" they meant in regard to Farenheit.
  • SketchySeaBeast 4y ago
    While true, the fact that all but 3 other nations managed to do it (though not with 100% transition - I still think of my height in feet and weight in lbs) means that "it's hard" isn't the only reason.
    • grujicd 4y ago
      And yet, metric system is not 100% used even in metric countries. TVs, monitors, speaker sizes, car rims and tyres, plumbing pipes, guitar scale length, etc are stuck in inches and used like that in the whole world. If 24" monitor sounds ok and you have no idea how big 61cm display is then it's safe to say we're also creatures of habbit and it's nothing specific to US.
      • SketchySeaBeast 4y ago
        I acknowledged that the conversion wasn't complete, but it has gone much much further than the United States nearly everywhere else in the world, so there's something specific about the United States that's preventing it from making even progressing.
  • bannedbybros 4y ago
    [dead]
• whythre 4y ago
  The US is huge, both geographically and with regards to population. Where would the political will for such a change come from? There is not much domestic desire to do so, and I am guessing few of the immigrants are chomping at the bit to institute the metric system in light of other, more pressing concerns.
• tgflynn 4y ago
  It's political. A significant portion of Americans, mostly conservatives, are unable to accept that anything not invented in the US could be superior to what they are accustomed to. There was a push toward adopting the metric system under Carter but since then the right wingers have been largely in control of the political discourse.
  • jjgreen 4y ago
    Er, they are aware that the inch, foot etc were not invented in the US right?
    • deleted 4y ago
      [deleted]
    • ahartmetz 4y ago
      "It's always been that way" is similar to "it was invented here" in that regard. Besides, the imperial units had local versions and some still do. There are AFAIK no US inches and yards, but US gallons and US pints.
    • zethus 4y ago
      Trusting us Americans to know history? Not a chance.
    • robertakarobin 4y ago
      You might be surprised at how many Americans think that Jesus spoke English. Source: am American.
      • seanw444 4y ago
        If Jesus exists, he probably can speak English. I'm sure that's not one of his limitations.
    • yardie 4y ago
      The US mile is different from the UK mile and US gallons are sufficiently different from UK gallons. Yes, our measurement system is almost entirely homegrown at this point.
• stcroixx 4y ago
  I'm not sure it's hard, is there evidence? Personally I don't think there's any valuable benefit, certainly not worth all the resulting disruption, and wouldn't advocate for it for that reason.
  • mbustamanter 4y ago
    Even more, several aviation reports use both. METARs use feet for cloud altitude and meters for visibility.
    • mfkp 4y ago
      METARs more commonly use statute miles for visibility (indicated by SM), not meters. But they do use things like Celsius for temperatures, and air pressure in hectopascals instead of inHg.
  • rybosworld 4y ago
    One anecdote in regards to the potential benefits: I've gotten into wood working the last few years and I've found that I'm significantly less likely to make a measurement mistake when I use metric. It seems like nearly all my measurement mistakes are when I did something in imperial. So why don't I use metric all the time? Because materials are usually sold in imperial units.
    • throwawaymaths 4y ago
      I love metric but the binary logarithmic inches subunits are fantastic for imperial with wood: Suppose you have a 30 cm piece and you need to evenly space 5 3.5 cm-wide wood planks on the 30cm piece. The decimal calculation will take you to a resolution you likely can't measure confidently (0.25 mm)
  • silvestrov 4y ago
    One obvious problem: if a US factory has a surplus of drain pipes they cannot export them. US pipes are 1.5 inch = 38.1 mm whereas EU use 40 mm pipes. So US companies cannot export surplus and will need new tooling when they want to export. That makes it much more difficult to expand into international markets.
• pmarreck 4y ago
  We tried it in the 70's. Signage everywhere (well, almost everywhere) used to have both kilometer and mile distances. Speedometers had both dials. Thermometers had two scales. Etc. etc. Then... it just never completely took. Then those changes went away. Part of it was political, surely (Carter spearheaded the metric change; Reagan coming in was super conservative), but I think you underestimate just how hard it is to get 50 halfway-independent states and millions of people to all agree on an entirely new system of measurement (not just of distance, but of volume, temperature etc.) when in millions of people's brains, the number 72 means "comfortable" (in Fahrenheit) and 100 means "hot!" (again, in Fahrenheit... you can't say "temps are in the triple digits!" in Celsius and have it mean anything other than that you're boiling), a tall man is "over 6 feet tall!", the average weight of an adult is 180 pounds, ovens get heated to 375 to bake something usually, shoe sizes (in inches), belt lengths (in inches), heck my baby's perfect bathwater temperature is exactly "100 degrees" (F, measured via infrared thermometer), going "100MPH" is VERY fast, 0 degrees F is VERY cold (-17C), etc. etc. It's still used in some spaces like science, but in places like tooling it's both... I have 2 sets of EVERY TOOL (well, every tool with a fixed size at least, like sockets and allen-head wrenches), the metric version and the imperial version, it's maddening- basically the worst of all options is to get stuck in the middle, and that's precisely what happened with tooling. Lastly, the digital tooling to automatically or easily convert is getting more common (a certain Reddit bot comes to mind which automatically converts any Imperial measurements cited in comments to metric), heck a browser plugin could probably do it for you
  • silvestrov 4y ago
    > just how hard it is Why is this always seen as harder for US states than European contries? At least all the states speak the same language and federal laws whereas EU has to work with however many languages and a more complex system of laws.
    • vel0city 4y ago
      Because its not 1800 anymore. Back when a lot of those European countries officially switched to metric the industrial revolution had only just begun. A huge chunk of the population was illiterate. Loads of people didn't deal with precise measurements in their day to day lives. Now days, everyone deals with measures almost daily and just about everyone is literate. And not every European country uses metric everywhere. Ask someone in the UK what their weight is, and if they don't tell you to buzz off they'll quite probably give you an answer in stone.
• knoebber 4y ago
  we don't want to: 12 is more divisible than 10
  • trgn 4y ago
    Metric system sucks for day2day measuring.
    • GalenErso 4y ago
      I have no difficulty estimating sizes and weights in kilometers, meters and centimeters, in tons, kilograms or grams, or in assessing the weather in celsius.
      • NDizzle 4y ago
        F > C.
        • bobbygunderson 4y ago
          Only down to -40
          • NDizzle 4y ago
            What I mean is that it's calibrated for humans, at least dumb ones like me. 0F, it's cold and the wind chill makes it miserable. 0C? That's 32F, which is technically freezing but I can still work on my cars outside in that weather. 100F, sweaty, hot, chugging water if you're outside. 100C? GG, you're dead.
            • cassianoleal 4y ago
              Honestly, that's just a matter of what you're used to. All my life I used Celsius, and even the dumbest of the dumb around me would always have a pretty good idea about how hot or cold a day was based on the temperature.
  • 4y ago
• ZeroGravitas 4y ago
  The US uses metric for some things, so it's partly transitioned. Feels like something that's only going to go in one direction, even if not quickly in some cases.
  • anotherevan 4y ago
    Judging by your popular media, you only use metric in science fiction shows where the distances between spaceships is so big the number is effectively meaningless. Longing for the day you start using kilograms instead of points for weight in your movies and tv shows. I always have to pause and grab my phone to convert.
    • timbit42 4y ago
      The hardest part is remembering that a kg is about twice as heavy as a lb so kgs are about half. This is accurate give or take about 10%. 2.2 lbs per kg. Multiply by 2 and add 10%. eg. 5 kg x 2 = 10 + 10% (1) = ~11 lbs. 0.45 kgs per lb. Divide by 2 and subtract 10%. eg. 11 lbs / 2 = 5.5 - 10% (0.55) = ~5 kg.
• baxtr 4y ago
  How can this be strange? I am saying this as a European. It’s simply customs. And the system works. Why change? It’s similar like asking why European football clubs wouldn’t want to change to the draft system of the US leagues. European soccer is commercialized to a degree which is unthinkable for Americans, who are commonly regarded as the bigger capitalists…
• yardie 4y ago
  Purely political. There were plans in place in the 70s and 80s. A particular political party politicised it as some sort of government overreach/UN/NWO meddling. And once they had the votes they voted to strip any mention of metric in federal usage. States followed shortly. I learned both metric and imperial measurements in elementary, middle, and high school. From what I understand they only use metric in science classes now. It didn’t make sense to me at the time. But the. I saw what happened to Core Curriculum, CRT, and US history. And it all makes a lot more sense.
  • throwaway894345 4y ago
    It's not "purely political" in any meaningful sense. It's just hard to transition something 330 million people use on a daily basis and the benefit is close to negligible. It's certainly among the least of any American's problems. Yeah, we have to have a set of metric sockets and a set of imperial sockets, but life goes on. Why doesn't the entire world standardize on language? That would provide far more benefit than standardizing on trivially-convertible units of measurement.
    • nicoburns 4y ago
      > It's just hard to transition something 330 million people use on a daily basis and the benefit is close to negligible I agree that it's hard, but not the benefit is negligible. The cost of not switching is paid every time an american company needs to work with a company from elsewhere in the world.
      • spoiler 4y ago
        Also, I feel like the linear nature (and being base 10) makes metric system easier to learn and have an intuition about. Although, another comment here said they find the metric system unintuitive for medium (which I assume are everyday) values. So, maybe I'm just biased on that belief
        • eternalban 4y ago
• regnull 4y ago
  The US does use metric system (you can easily go and buy 2 liter bottle of Coke). What you probably mean, why the metric system is not mandated as the only one acceptable for basically everything? Why indeed.
  • mcherm 4y ago
    No, I think the question is why the metric system isn't used by default for most purposes -- like road signs.
    • cassianoleal 4y ago
      I suspect that road signs don't use metric in the US and the UK for safety reasons. Especially speed signs. Someone who's used to thinking in miles per hour suddenly seeing a sign in km/h will likely speed up to approximately 150% of the legal limit.
      • timbit42 4y ago
        Canada had both numbers. The kph was on top and larger. The mph was below and smaller, obviously. Now the mph has been removed for quite some time.
  • anotherevan 4y ago
    Judging by your popular media, you only use metric in science fiction shows where the distances between spaceships is so big the number is effectively meaningless. Occasionally hear grams for small amounts. That's it.
• iamben 4y ago
  I mean the UK still does roads/cars in MPH rather than KPH. Lots of people will still give their (body)weight/ask for (body)weight in stone and height in feet and inches, although I think that's slowly changing to KG and CM. It's a strange one though, isn't it? I was watching an exercise/nutrition video on YouTube earlier and the presenter was saying "to work out how much protein a day you need, multiple your bodyweight in lbs by X and that will give you the protein number in grams." It seemed so bizarre to combine the systems. Edit: Just to add - in the UK we're taught entirely in metric in school, the bits mentioned above are just hangups / how it's done.
  • nemo44x 4y ago
    You also use "stone" and "furlong" in certain contexts and drive on the left side of the road. I think it's awesome and makes the UK unique in some regards. It's what culture and customs are all about.
    • laserdancepony 4y ago
      I agree, now reintroduce the archaic old currency system to replace the metric pound division you have now. That would really add a certain quirky touch to your financial institutions, foreign trade and tourists will surely love it! There is more than one way to lead your country back into the late neolithic, just go on.
    • iamben 4y ago
      Yeah, I mentioned stone! My loose experience is that a good percentage of people who do something relating to fitness end up talking about their bodyweight in kilos (the scales in the gym are usually in kg, for instance). But most people when talking about bodyweight would say "I'm X stone X." In the 40+ years I've lived here I've only ever heard furlong used in the context of horse racing and the actor that played John Conner in Terminator 2... Re the driving - about 35% of the world are on the left!
    • beardyw 4y ago
      Driving on the left is not unique. About one third of the world does that.
• gtmitchell 4y ago
  The vast majority of organizations in the US already use the metric system in places where the metric system makes sense. Basically everyone who wants to use it is already using it. For everything else, what's the point in the government mandating it? There's no political desire for it because society in general doesn't care, and society doesn't care because the costs outweigh the benefits. There's no practical advantage to the average person to learn their height in meters instead of inches and feet, or to have to start shopping for hectograms of food when ounces work just fine.
  • adregan 4y ago
    In 1821, Secretary of State and the future president, John Quincy Adams released a report on weights and measures to congress. He had labored over the report obsessively for more than 3 years as he was absolutely fascinated by the metric system. Adams expected the report to catch fire and result in the adoption of the metric system. In actuality, it was a dud, and congress did nothing about it. His wife however noted in her diary “Thank God we hear no more of Weights and Measures.” Society not caring about this issue is nearly as old as the country itself. But I can imagine John Quincy Adams, if alive today, would probably be just the type of person posting an “Ask HN” question on the US adoption of the metric system.
  • laserdancepony 4y ago
    Never seen a hectogram in Europe, everything less than a kilogram is labelled in grams. Combined with the concerns of another commenter who scratched his head about having to give his body length as 183cm, I come to the conclusion American brains overflow after 99.
    • thefz 4y ago
      In Italy we use "etto" (100g) a lot, especially with groceries/deli.
• sidewndr46 4y ago
  I grew up in the US. I only learned the metric system. There was never any point at which we used the customary units.
  • whimsicalism 4y ago
    You use celsius? You must have gone to a specialized school then.
    • sidewndr46 4y ago
      Public school in Alabama. Never once used Fahrenheit for anything. Most stuff actually done in Kelvin, although as I am sure you know there is little difference.
      • whimsicalism 4y ago
        What happens when you check the weather or ask anyone else the temperature or check your thermostat? Are you saying that you never used Fahrenheit for schoolwork? Or for anything?
        • sidewndr46 4y ago
          Never used Fahrenheit in school for anything. I mean you could in theory if you wanted when asked on an exam "what is the boiling point of water?" write something other than "100 C". I'm not aware of anyone that did. We certainly never adjusted the thermostat in school, if that is what you are asking. If someone asked me to read the thermostat at home for example, I just told them the numbers on it. It's not like "72 F" is radically different from "72 years old".
          • whimsicalism 4y ago
            What I fail to believe is that you don't have an intuition for 72 F or 30 F, etc. What I can believe, but would be nonetheless very surprised by, is that you have better intuition for 28 C, 25 C than you do for the equivalent Fahrenheit units if you were raised in the US.
• jandrewrogers 4y ago
  The issue with switching to metric in the US is that there isn't much practical benefit that would offset the downsides. Technically, the US switched to metric a long time ago. No one uses it in their day-to-day life. The US is economically big enough that it can easily sustain using its own standards. Since there is no practical benefit, most people don't care and aren't going to go to the effort. A vast amount of non-metric physical tooling already exists -- replacing it would be extremely expensive. For things like engineering, it doesn't matter because the units have to follow the values anyway; there are many common unit systems in engineering that are neither metric nor US imperial, and working across unit systems is something you always have to do anyway. tl;dr: low ROI and high cost to switch
• freeopinion 4y ago
  Is there somewhere in the U.S. that doesn't use metric? 2L bottles of soda, 2.4L engines, 100m races, 5K runs, 2cc injections, 20 kilo drug busts, 11mm wrenches, M5 screws
• whimsicalism 4y ago
  The US is very conservative and broad swathes of the population hate "European" ideas.
  • seanw444 4y ago
    And in many situations, I'd agree with those swathes. But when it comes to metric vs. imperial, I'd have to agree that metric is more cohesive and sleek.
• lowbloodsugar 4y ago
  Tribalism and identity politics.
• wintorez 4y ago
  Adam Ragusea has an excellent video on this topic: https://www.youtube.com/watch?v=1OeoBbjwEFg https://www.youtube.com/watch?v=1OeoBbjwEFg
• grecy 4y ago
  Driving the Alaska Highway there are a bunch of markers for historical things along the road like bridges & lookouts. The majority of the Alaska Highway is actually in Canada, and so all the signs are now in Kilometers and they say things like "Historical marker 1550km (old mile marker 965)". I was standing at one taking a look and an older couple came over and loudly exclaimed "It's a damn sacrilege to the memory of those young men who built the road they would go and change it like that." They were adamant changing it to kilometers was unacceptable, because old reasons.
  • toss1 4y ago
    Sounds like the people objecting to the introduction of time zones due to speed of rail transport, saying that "they are defiling God's time!", as if it was God that invented it, and not humans that decided that Noon was conveniently the point where the sun was highest in the sky and crossed the meridian.
• harimau777 4y ago
  A difficulty that I find is that metric as commonly used is more awkward for estimating. For example, I find that metric distance as commonly used doesn't have a good equivalent to feet for working with medium lengths. By "as commonly used" I mean that, while I could theoretically use decameters, in practice average people seem to only use millimeters, centimeters, meters, and kilometers. That makes it difficult for me to estimate medium lengths in metric. For example, it's awkward to describe someone as 1.83 meters or 183 centimeters tall. It is much easier to describe them as 6 feet 2 inches. To a somewhat lesser degree, the same seems to be true for volume. In practice people only seem to use milliliters and liters. That leaves me with no good equivalent to cups or gallons.
  • spoiler 4y ago
    > For example, it's awkward to describe someone as 1.83 meters or 183 centimeters tall. It is much easier to describe them as 6 feet 2 inches. Lol, funny how I'm the exact opposite. When someone says their height in meters I have a pretty good idea of their height, where as for feet, I always have to do maths in my head first. Same for volumes I wonder if it's just a matter of better familiarity with one system over the other
  • kwanbix 4y ago
    Why would you want to describe somebody as 183 centimeters tall? Even if there is a good reason, it is not a problem at all. It is very easy to understand you mean 1.83 meters. Same way you don't tell the height of a person in inches alone, you normally don't tell it in centimeters.
  • pier25 4y ago
    > It is much easier to describe them as 6 feet 2 inches. That's purely subjective. I'm from Europe and even though I'm a bit familiar with imperial units, I almost always need to use Google to convert feet and inches to metric. And no one is going to convince me that fractional stuff like 3/16 inches is easier than 4.7mm.
  • maartenh 4y ago
    It's what you're used to. Cups and gallons are confusing to me! In some of my Dutch cook book, there are mentions of cups. But mostly as a relative unit; add one cup of X, two cups of Y. For absolute amounts, the metrics system just makes more sense, as it nearly combines the different quantities without weird conversion constants. Note that in medical or scientific environments, centiliters are actually used. But then again, we still use milimiter-mercury as a unit in medicine too ;) [0] [0] https://en.m.wikipedia.org/wiki/Millimetre_of_mercury https://en.m.wikipedia.org/wiki/Millimetre_of_mercury
• threemux 4y ago
  The better question to ask is what is the benefit? For everyday usage by regular people, it's not clear to me that metric is superior if you didn't grow up with one or the other, hence the lack of push for a change. In fact, I've seen the argument made that feet, inches, miles, cups, teaspoon, Fahrenheit, etc are superior to meters, centimeters, km, mL, Celsius, etc for everyday use. As I've seen it presented, this argument contends that centimeters are too small, while meters are too large for many common things you want to measure, such as the height of a person. Likewise cups and teaspoons are actual objects that you could visualize and get a general sense of the amount without even knowing the actual measurement. Same kind of thing for Celsius: the most common usage of temperature measurement for the average person is air temperature. For the set of air temperatures commonly experienced on Earth, Fahrenheit provides more precision.
  • brg 4y ago
    Although downvoted, this is the right response. Its not harder for the US to move to metric than it was for any other large country. The change hasn't happened because there isn't utility in using metric, and a lot of cost. Of course, there are clear examples when metric is both easy an intuitive. In everyday usage there are many cases where Imperial is beneficial (cooking -- metric is poor for individual servings, height and weight metric is inefficient as the modal height starts with the same digit, temperature requires more digits).
• kibwen 4y ago
  The US is moving toward the metric system, slowly. Federal efforts may have largely stalled during the Reagan admin (though things like requiring metric labeling on products still eventually made it through), but there's nothing stopping individual states from requiring metric in more places, e.g. road signs. As for why no state has bothered to do so yet, it's likely because there's currently a thousand more pressing issues to expend political capital on first, many of which are existential crises in a way that metrication is not.
• downvotetruth 4y ago
  US standard may be worse, but the USA is the leader of the free world and is not about give up the choice to use other systems and bases like duodecimal and bow to some arbitrary tyrannical French system imposed by a despot that declares decimal to be the end all be all.
• vel0city 4y ago
  This Johnny Harris youtube video does a decent job describing this. It would take at least a generation before the US population really got used to using metric places. https://www.youtube.com/watch?v=nRnuY1Vao0o https://www.youtube.com/watch?v=nRnuY1Vao0o The timestamp where he's directly talking to what I mean: https://youtu.be/nRnuY1Vao0o?t=1192 https://youtu.be/nRnuY1Vao0o?t=1192 In it, he mentions the main reason why he doesn't use the metric system: he can't. Inches and feet and miles and ounces and pounds are so deeply ingrained in his mind. Even when he tries to relate to metric, its always in relation to imperial units, because to him its not about 30 centimeters its about a foot. Its not about a kilogram, its about two pounds. He can do the conversions in his head usually, but actually visualizing how far 5km is means converting it to miles which he can conceptualize. Its like learning another language. Sometimes people are really great about just remapping their brain, but many people just end up internally translating things instead of actually deeply adopting the language. And if they're going to just be constantly translating it, it'll just be uncomfortable for them, and they won't want to do it. Because to a certain extent, what's the harm in my speedometer being primarily miles per hour? What's the harm in having a sign say "Rest Stop 5mi" instead of "Rest Stop 8km"? I'm pretty similar to Johnny here. I can easily visualize ~300mi on a map. 300km? I know it is a good bit shorter than 300mi, but just at a quick off the top of my head I wouldn't quite know how far that really is. I'd be just doing the conversions in my head which takes me a second to think "ok, so divide by 1.6ish, so that's a little over 180 miles..." which I'd then use to conceptualize how far that is. Changing to metric isn't just changing all the highway signs. Sure, that could be done in just a few years if we wanted to. Its changing how everyone actually thinks, how everyone is actually wired. That's what holds up the US from actually adopting metric. But in the end, I still do use some metric. This drink I'm drinking has its nutrition label in grams/milligrams/Calories. My child got 1mL of iron supplements and vitamins this morning. It will be a long series of small steps before people get used to the change. Just swapping all the road signs overnight isn't going to lead to very happy people. Back when most of Europe adopted metric, 40% of the population were illiterate. Tons of people didn't really deal with a lot of weights and measures in their daily lives. We live a very different world today than when metric was adopted in most of the world.
• jeffreyrogers 4y ago
  Because the benefits of switching seem relatively limited for the cost.
• Isinlor 4y ago
  Actually USA is using the metric system. They just apply their weird conversions on top of the metric system, but fundamentally they use the definitions of the International System of Units. E.g. Pound is legally exactly 0.45359237 kilograms where kilogram is defined by setting the Planck constant h exactly to 6.62607015×10^−34 J⋅s (J = kg⋅m2⋅s^−2), given the definitions of the metre and the second. Previously kilogram was a block of metal stored in France. But the copies of kilogram were diverging and there was no way of knowing where the changes were coming from. So now the kilogram is defined with regard to the physical properties of the universe as opposed to specific object. E.g. a meter is exactly the distance traveled by light in a vacuum in 1/299792458 seconds. Where second is exactly the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.
• nemo44x 4y ago
  The imperial system has a great UX and is as precise as metric so there's no real incentive to change. For science metric makes a lot of sense of course and we use it there (mainly!) and we use it for trade, but for day-to-day use among people, why change? It's very intuitive in terms of unit sizes being very much at human scale. Even when doing woodworking/carpentry, the imperial system is really nice being based on 12 in many aspects. The foot/inch system is great for day to day use. The centimeter is too small and the meter too large, for example. I also think it's nice that different countries do things differently. It gives you identity and makes the world a more diverse and interesting place. I love that the UK has measurements like "stone" when describing a person's weight and that they use miles per hour for driving and kilograms for buying food and drive on the left side of the road.
• Caduceus1 4y ago
  Once screen producers start advertising their products in metric, the change will come.
• robgibbons 4y ago
  As the joke goes, there are two types of countries: Those that use the metric system, and those that have been to the moon. All joking aside, the metric system is widely used in the US for guns and drugs.
  • spoiler 4y ago
    Why guns? I understand drugs since it's such small scales (does the Imperial system even have a good way of expressing those?) Edit: I know you joked, but now I wonder if NASA used metric or imperial system back then
• xzyyyz 4y ago
  1. Inertia. It is difficult to switch measurement in people's heads. For example, I grew up in metric environment, but I did not drive car. So for me, local sizes are in meters, but car speed, distances are in miles :-). Home temperature is in Celsius, but grill or oven are in Farenheits. :-) 2. Cost. There is a direct cost (like remarking everything), and indirect -- all the chaos and errors because of mixing up units. To foot the bill is hard sell in Congress. 3. Peer pressure: because of size of economy, US can request whatever it wants from partners. UK had to move to metric when joined EU. That said, I am very supportive of metric. We are paying price for the imperial units. Every car shop has two set of wrenches. (BTW, it is metal, production -- read climate impact. May be not big, but still impact we could avoid.) All the software must show controls for units. We need to train professionals (like doctors) to live in two worlds. And the list is endless. [Did I mention translation bugs? For example, outside temperature translation is 9/5 Celsius + 32, but difference between outside and inside is 9/5 Celsius. :-( -- real bug I caught in critical industrial control system. ] I am not sure where does US stands today. For example, I think metrics is teached in school. Most food is dual marked. So, maybe, it is not rejection, but rather slow move?
  • ryandrake 4y ago
    > 2. Cost. There is a direct cost (like remarking everything), and indirect -- all the chaos and errors because of mixing up units. To foot the bill is hard sell in Congress. Maybe for things like road signs where a lot of travel and labor would be required to change everything. But for most commercial products, you don't have to change everything all at once or make some kind of big retooling effort. Company would just have to pick a day, and from there on, instead of printing "16 fl. oz." just start printing "473 ml" on the package.
    • acjacobson 4y ago
      A lot of products already have both printed on the package.
• hprotagonist 4y ago
  lots of sunk costs. No real interest.
• cjbgkagh 4y ago
  I figured it was a cheap form of protectionism. While it makes it harder for exporters it also makes it harder for importers. It helps maintain a separate local tooling and consumable pipeline which helps with war fighting, it probably also makes money for donors. I think the sheer scale of Chinas exports can and has easily overcome that hurdle so the protectionist aspect is now much less relevant.
• ishjoh 4y ago
  Having grown up in a country into adulthood that used metric and then moving to the US there are certain things that are nice about the US system. In particular a foot is an extremely intuitive unit of measure. It covers a number of use cases better than meters or centimeters. I also prefer Fahrenheit now that I'm used to it. Fahrenheit has a nicer range for the temperatures we live our lives at, whereas Celsius compresses that range so much. Unintuitive US units: Miles - I still have a very hard time with how far this is, km was much nicer.
  • Balgair 4y ago
    A good metric I once heard was: Fahrenheit is what humans feel Celsius is what water feels Kelvin is what atoms feel Also, for converting between km and miles, using the Fibonacci sequence is a 'good enough' estimator. 5 miles is ~8 km, 21 miles is ~34 km. 13 km is ~8 miles, 55 km is ~34 miles. Drop or add decimals to get to numbers not in the sequence. If you want to know what 6 km, use 5.5km and you see that its a bit over 3.4 miles.
    • thiht 4y ago
      That makes no sense. Kelvin and Celsius are the same, just with a different 0. I know exactly what a temperature of 0°C, 10°C, 20°C or 30°C will feel like, and I’m pretty sure I’m human.
      • muli_d 4y ago
        I think that the idea is "what it feels like in a scale of 0 to 100". So, in Celsius, water are "very cold" (=freezing) at 0 degrees but "very hot" (=boiling) at 100 degrees. Same with Fahrenheit: 0 is extremely cold while 100 is very hot. I get the logic but I am too used to Celsius at this point, just like you.
  • tzs 4y ago
    > I also prefer Fahrenheit now that I'm used to it. Fahrenheit has a nicer range for the temperatures we live our lives at, whereas Celsius compresses that range so much. What I don't understand is why Celsius even exists. For length, area, volume, and mass replacing the old units makes a lot of sense to move to a power of 10 relation between the base units for those things and the smaller and larger units derived from those, and to name those derived units by prefixing the base unit, and to use the same prefixes across different kinds of units. So with metric we just need to learn one basic unit (meter, meter^2, meter^3, gram), one set of prefixes (milli, micro, centi, kilo, etc) and then we are all set. Compare to English where the ratios between consecutive names units for a given kind of unit vary, and knowing them for one kind doesn't help with other kinds (e.g., knowing inch x 12 = foot, foot x 3 = yard, yard x 1760 = mile does not tell you anything about how many ounces are in a gallon). Although one might argue that the multipliers in English units tending to be of the form 2^n 3^m makes a lot of problems easier than the 10^n multipliers of metric, there are also cases where the 10^n multipliers makes things easier, and metric using the same prefixes across different types of units is definitely a win for usability. For temperature though we generally don't use smaller or larger units, so we don't have a question of what kinds of multiplier to use for bigger or smaller temperature units. All it appears that Celsius does is make the degree bigger, and change the origin. (When first proposed it also changed the direction...0 C was the boiling point of water and 100 C was the freezing, but not long after Celsius revised his system so increasing numbers corresponded to hotter like most other systems). Some say the argument for Celsius over the older and already widely used Fahrenheit is that basing the scale on the freezing and boiling points of water was easier to reliably reasonably reproduce than the reference points of Fahrenheit. But that argument really doesn't fly. If the problem was the reproducibility and reliability of the reference points the obvious solution would be to change the definition of Fahrenheit so that 32 F is the freezing point of water and 212 F is the boiling point of water. That would fix the definitional problem just as well as Celsius did without requiring new thermometers.
• meepmorp 4y ago
  It would take work and there's no pressing reason to do it. I can imagine what it would be like if you told me you went on a 5 mile hike with your 6'6" friend on a 63 degree day. If that was 8km, 2m, and 17 degrees I have much less intuitive sense of what happened. And I don't see much advantage to switching - it doesn't matter which units you use so long as you're consistent within the domain of use. What's the downside?
• sbaiddn 4y ago
  ... we have better things to spend trillions of dollars on than change a metric based system with another? Honestly, HN will moan about how much work and how dangerous the stupidest clock or UTC change is but keep proposing to change every unit used by a quarter of the world's economy. Blows my mind.
• haunter 4y ago
  As a European I only get mildly upset when reading US recipes. "1 cup of flour" Just the fact that it's a measure of volume [0] instead of weight is already stupid imo. I pretty much stopped reading recipes where there are no metric units (weight!) provided, preferably in grams. 0, https://en.wikipedia.org/wiki/Cup_(unit) https://en.wikipedia.org/wiki/Cup_(unit)
  • nycjay 4y ago
    Isn't the gram a unit of mass, not weight? https://en.wikipedia.org/wiki/Gram https://en.wikipedia.org/wiki/Gram
    • cassianoleal 4y ago
      You are correct. At the same time, the way we measure mass is by measuring weight and having the balance approximate a conversion. I imagine most balances use sea level gravity for that but I can't be bothered to do research. :D
    • kyriakos 4y ago
      Makes no difference if cooking on earth though
• jcranmer 4y ago
  There's a few reasons for this. First, the 10-based units of the metric system isn't in fact its biggest utility--it's the fact that everyone agrees on the size of the meter, as opposed to the traditional foot, where every country had its own slightly different length of a foot. With those other customary units pretty thoroughly dead, there's little confusion as to the size of a foot. Second, as a few people have noted, customary units actually tend to be somewhat more convenient to use than a strict metric system. Note that the metric system comes up with 1 liter = (1/10 m)^3 or 1 hectare = (100 m)^2 to try to synthesize useful volume or area units from regular length. In many regards, Fahrenheit is really a more comfortable measure of ambient air temperature than Celsius is. The metric system's fastidiousness in 10-based increments is more useful if you're doing tasks like measuring the area of an irregularly-shaped plot of land, or scientific calculations, but is less useful for more pedestrian tasks like measuring out how much flour you need for the cake you're baking. Third, it takes a very long time (at least a generation) for people to get used to new units. You see this in the UK, where imperial units are still used for lots of things despite official metrication. Residual use of customary units for things like cookbooks or tool dimensions will take a very, very long time to root out. Finally, there are lots of things that depend on the precise units that are hard to move. The US actually has two definitions of length, the international foot (which has 1 in = 2.54 cm exactly), and the survey foot (which has 39.37 in = 1m exactly). It's been trying to phase out the survey foot for decades, and that's still in progress because quite literally the coordinate planes that are used in several states for plotting land in the US are based on the survey foot. Even small differences in units there can lead to inaccuracies of several feet in determining the bounds of your plot of land.
  • jfengel 4y ago
    I think people very much miss your first point. The powers-of-tens thing just isn't as common an operation as people seem to imagine. Scientists work in scientific notation directly on the base unit. There's no need to convert to megamoles or hectoliters or anything else. If you're stitching together fourteen 2-cm pieces of cloth, the total length is 28 cm, and nobody cares if it's also 280 mm and .28 m. It's not that people never do these things. It's just that people talk about the English system as if converting from feet to miles is an onerous daily operation. If you're working in feet, you stay in feet. I'd say that the more useful conversions in the metric system are when you're converting between different unit types, which aren't ten-based but are defined in convenient terms: a kilogram of water takes up 1 liter; a milliliter is 1 cm on a side. These are not-uncommon operations, and the factor-of-ten doesn't really matter. People talk about the prefixes because they're easy to understand, and that's great. But prefix switching just isn't as important as it sounds.
• bokohut 4y ago
  Not answering the OP but instead sharing what I am having to do to accommodate others while learning a thing or two through that accommodation. Some here may recall the significant NASA failure where imperial and metric were mixed leading to a costly outcome(1) and that is what I want to avoid. While I am not launching rockets I do require extremely accurate calculations for my objectives. As an American, born and raised, the U.S. way is baked into everything that I do; however now that I am engineering a global hardware based solution that sees neither race, nationality, or creed all my engineering calculations are presented in metric in the final “pitch”. As an American I have done all my "internal thinking" using what I know but to reach a broader market for my potential global audience my documentation carries the reader, should they be Imperial based, through the metric conversions for those with the mathematical interest. My past experiences have guided me to spend the time now for this activity as a function of explicit documentation presenting the engineering and this is time very well spent since explicit written calculations with variables and constants clearly labeled leave much 'less' room for error when assumptions are eliminated, regardless of your unit of weights and measure. (1)https://www.newscientist.com/article/dn17350-nasa-criticised-for-sticking-to-imperial-units https://www.newscientist.com/article/dn17350-nasa-criticised...
• ryandvm 4y ago
  Momentum is the most powerful force known to mankind. "That's how we've always done it" drives so much of what humans do it's not even funny. Speaking for my own countrymen, we still mint the penny, write checks, wear ties, shake hands, use imperial, speak English, work 40 hours a week, have 2 political parties, tip waitstaff, etc. not because they are objectively the best solutions, but because that's how we've always done it.
• irvingprime 4y ago
  It's not hard. We just don't care.
• wdr1 4y ago
  Nit: For those saying the US uses Imperial units. It doesn't. The US uses something called US Customary Units: https://en.wikipedia.org/wiki/United_States_customary_units https://en.wikipedia.org/wiki/United_States_customary_units Both US Customary & Imperial derived from British units but they have always had large differences. There was an effort to reconcile the two but it was an abandoned when Europe decided to adopt the metric system. Still differences remain: https://en.wikipedia.org/wiki/Comparison_of_the_imperial_and_US_customary_measurement_systems https://en.wikipedia.org/wiki/Comparison_of_the_imperial_and...
• ballenf 4y ago
  As seamless language translation becomes ever more integrated into our communications, it will matter less and less what languages, much less measurement system people use.
• anotherevan 4y ago
  Reading all the reasoning, both for and against, reminds me that ever since I heard about confirmation bias I see it everywhere. :-)
• mikewarot 4y ago
  The switch to Metric in the US was made easier by a personal decision of Carl Johansson... (backed up by wikipedia)[1] In the early 20th century, the U.S. inch was effectively defined as 25.4000508 mm (with a reference temperature of 68 °F (20 °C)) and the U.K. inch at 25.399977 mm (with a reference temperature of 62 °F (17 °C)). When Johansson started manufacturing gauge blocks in inch sizes in 1912, Johansson's compromise was to manufacture gauge blocks with a nominal size of 25.4mm, with a reference temperature of 20 °C (68 °F), accurate to within a few parts per million of both official definitions. Because Johansson's blocks were so popular, his blocks became the de facto standard for manufacturers internationally, with other manufacturers of gauge blocks following Johansson's definition by producing blocks designed to be equivalent to his. [1] https://en.wikipedia.org/wiki/Gauge_block https://en.wikipedia.org/wiki/Gauge_block
• joshka 4y ago
  Please rewrite this post, but in every 10th word, you should swap the letters e and i. Tomorrow rewrite this post, but instead make it every 9th and 10th word. Ivintually thes well bi feni and iviryoni well undirstand that i and e ari swappid. But thiri well bi a bet of temi to git adjustid wheli that happins.