# The United States and the metric system. **URL:** \ **Category:** Factual Questions\ **Created:** [October 17, 2009, 6:01am UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126 "2009-10-17T06:01:02Z")\ **Posts on this page:** 20\ **Page:** 5
**Author:** ![Shig](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Shig](https://boards.straightdope.com/u/Shig)\ **Post date:** [October 20, 2009, 3:46am UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/81 "2009-10-20T03:46:06Z")
> [@Chronos](#): > > Way to take that out of context. Between the US, Liberia, and Burma, yes, I’d say that the US is the only one worth mentioning. France, Australia, the UK, Russia, India, China, Japan, etc. are also worth mentioning, but they all use predominantly the metric system (even if there are still a few holdouts of the old system in British beer and the like). Sorry Chronos, I’m still new and shouldn’t be a smartass with people that don’t know me. My intent was to take it out of context and mock the type of folk that would make such a statement and “mean it”. 🙂 ---
**Author:** ![Candyman74](https://avatars.discourse-cdn.com/v4/letter/c/ad7895/32.png) [@Candyman74](https://boards.straightdope.com/u/Candyman74)\ **Post date:** [October 20, 2009, 1:37pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/82 "2009-10-20T13:37:45Z")
> [@Chronos](#): > > The US is the only country worth mentioning that still uses the old “customary” units predominantly. Some specific units like miles might still be used in one or two other places, but the system as a whole is distinctively American. And while Halloween is known in Europe and places which derive from European culture, it’s observed in the US to a greater extent and in a different way than it is in Europe: It’s just a given here that any particular group of people is likely to have a Halloween party, and put up decorations, and participate in Trick-or-Treating (either giving or receiving), etc. But it _is_ a British system. "Imperial units or car asks me “US or Metric?” I’m like “Uh… neither?” Eh, it’s a pet peeve; inconsequential, admittedly. As for Halloween - we’ve celebrated with costume parties, trick-or-treating, decorations, etc., certainly for all of my life (I’m 35). And as we all know, Halloween has existed for longer than the US has! Again, calling it “American” just seems wrong to me, expecially when it already has a perfectly servicable - and more accurate - name. I guess it doesn’t matter. Just niggles at me when I see it! I keep expecting to see Christmas referred to as an American holiday and the English language renamed “American”. 🙂 ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [October 20, 2009, 1:50pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/83 "2009-10-20T13:50:45Z")
> [@Candyman74](#): > > But it _is_ a British system. "Imperial units or car asks me “US or Metric?” I’m like “Uh… neither?” Eh, it’s a pet peeve; inconsequential, admittedly. It’s originally British, but there are some significant differences between the US system and the old British system, e.g., different fluid ounces, pints, quarts and gallons. So it makes sense to call it the US system. ---
**Author:** ![Candyman74](https://avatars.discourse-cdn.com/v4/letter/c/ad7895/32.png) [@Candyman74](https://boards.straightdope.com/u/Candyman74)\ **Post date:** [October 20, 2009, 2:08pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/84 "2009-10-20T14:08:22Z")
> [@Giles](#): > > It’s originally British, but there are some significant differences between the US system and the old British system, e.g., different fluid ounces, pints, quarts and gallons. So it makes sense to call it the US system. The day my speedometer starts reporting fluid ouces, pints, quarts and gallons is the day I stop driving! ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [October 20, 2009, 2:11pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/85 "2009-10-20T14:11:25Z")
> [@Candyman74](#): > > The day my speedometer starts reporting fluid ouces, pints, quarts and gallons is the day I stop driving! But your fuel economy is in miles per gallon, and that depends on the size of the gallon. ---
**Author:** ![Candyman74](https://avatars.discourse-cdn.com/v4/letter/c/ad7895/32.png) [@Candyman74](https://boards.straightdope.com/u/Candyman74)\ **Post date:** [October 20, 2009, 2:21pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/86 "2009-10-20T14:21:31Z")
> [@Giles](#): > > But your fuel economy is in miles per gallon, and that depends on the size of the gallon. So there absolutely isn’t an option for me. I use miles and British gallons. My only options according to my car are: Kilometers - Litres Miles - American Gallons There’s no option for: Miles - British Gallons It probably only requires an extra 15 seconds when originally writing the software to include it. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [October 20, 2009, 3:27pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/87 "2009-10-20T15:27:02Z")
> [@Candyman74](#): > > So there absolutely isn’t an option for me. I use miles and British gallons. My only options according to my car are: > > Kilometers - Litres > Miles - American Gallons > > There’s no option for: > > Miles - British Gallons > > It probably only requires an extra 15 seconds when originally writing the software to include it. Imperial gallons, actually; they were used throughout the Empire. Which is why in Canada, when cars are sometimes advertised with ‘miles per gallon’, it should specify Imperial or US. Makes about a 20% difference! [Here’s an example, a Toyota Yaris hatchback.](http://www.toyota.ca/cgi-bin/WebObjects/WWW.woa/37/wo/Home.Vehicles.Go.YarisHatchback-BXHIbF7YV0EXyVUSOVvQB0/3.7?v124040e.html) Quoted at 44 mpg combined cycle on the ‘Capacity’ tab of that web page, and the fine print says miles per Imperial gallon. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [October 20, 2009, 3:43pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/88 "2009-10-20T15:43:55Z")
> [@Chronos](#): > > It’s just as easy to say the numbers in either system, but how about _using_ them? If you want to do anything at all with the numbers, you want to use the metric system. > > An example: I have a rectangular fish tank, and I want to know how much water it takes to fill it. In metric, I can measure the length, width, and height in centimeters, multiply them, and I have the volume in milliliters. Divide by 1000, and I have liters. In American, by contrast, I measure the length, width, and height in inches, multiply them, and then divide by 231 to get gallons. 231! Tell me, how many of you knew that there were 231 cubic inches in a gallon before this thread? And even after this thread, how many of you will remember that tomorrow? Except, you already know the metric conversions. Granted, the math is simpler in decimal units, but it doesn’t negate the fact that you still have to learn how many milliliters are in a given amount of cubic centimeters. If your measurements involve too many different prefixed units, then you run into similar problems as with English units. (By “you” I mean common people that don’t do conversions every day of their lives.) Once you’re accustomed to a system of measurement, it doesn’t really matter how they’re divided up; you become proficient with them. How many people that don’t work with SI units regularly will remember tomorrow that volume measured in centimeters yields milliliter results versus some other unit? ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [October 20, 2009, 3:50pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/89 "2009-10-20T15:50:03Z")
> [@Apollyon](#): > > NZ changed over in '67, and there were detractors then too , who claimed that the new-fangled decimal currency was too complicated, unlike good old £sd… just like metric measurement is more complicated than feet, yards, chains, furlongs, pounds, stone, pints, gallons, etc, etc. 🙂 An elderly friend of mine who grew up in England still have all the old units firmly planted in his mind. That said: Sweden is (almost) totally metric. The only occurrences of other units are lumber industry and carpentering, lumber because the US is a big trade partner and carpentering as a result of that, I suppose, plus beer. When I first launched a career as a beer drinker the standard measure was half a litre, 500 ml. For some reason the glasses have steadily shrunk during the last thirty years down to 400 ml, or even less, with no allowance for a head. The emergence of British style pubs, though, has brought with it pint glasses which dedicated pub goers see as a blessing, although you can never trust the bar staff to actually give you a whole pint, but it’s still a step in the right direction. ---
**Author:** ![Myglaren](https://avatars.discourse-cdn.com/v4/letter/m/f1d935/32.png) [@Myglaren](https://boards.straightdope.com/u/Myglaren)\ **Post date:** [October 20, 2009, 6:45pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/90 "2009-10-20T18:45:46Z")
When I moved to Sweden I was used to only Imperial measures and had to learn the language and the measurements PDQ. Found converting to metric quite easy. The first time my girlfriend took me to a pub, I found beer in Litre glasses rather daunting. Soon overcame that one too 🙂 ---
**Author:** ![TBG](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@TBG](https://boards.straightdope.com/u/TBG)\ **Post date:** [October 20, 2009, 10:09pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/91 "2009-10-20T22:09:06Z")
> [@Chronos](#): > > An example: I have a rectangular fish tank, and I want to know how much water it takes to fill it. In metric, I can measure the length, width, and height in centimeters, multiply them, and I have the volume in milliliters. Divide by 1000, and I have liters. In American, by contrast, I measure the length, width, and height in inches, multiply them, and then divide by 231 to get gallons. 231! Tell me, how many of you knew that there were 231 cubic inches in a gallon before this thread? And even after this thread, how many of you will remember that tomorrow? And how many won’t be able to just look it up in under a minute? It’s not like we have a way to do that… Oh wait. And just how often do you need to know how much water it takes to fill a fish tank, anyway? Once? Big freakin whoop. Unless you own a fish store or something. On the other hand, some American measurements are actually better than metric. Take the foot. You can get an EXACT measurement for a third of a foot. 4 inches. What’s a third of a meter? .33333333333333repeatuntilinfinity meters. Oh, slightly less precise, but hey, at least divide by ten comes out to exactly .1 meter! Then again, that’s no more precise than .1 foot or 1.2 inches… No, not all American units are going to have that exact advantage, I mean, miles to feet, that’s probably pretty weird, but come on, you measure length of objects or small areas in feet, and long distances in miles. Might as well complain about the number of AU in a lightyear. BTW, is the fishtank question in some book about how to show how “awesome” metric is or something? Because I’ve seen it come up in many different [del]arguments[/del] discussions of the metric system, on many different boards. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 20, 2009, 10:35pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/92 "2009-10-20T22:35:12Z")
> [@jtgain](#): > > Agreed. Pro-metric people talk about how “easy” those units are. “See water freezes at 0C and boils at 100C!” > > But who cares? Real life measurements don’t hinge on the boiling point of water. A 0 to 100 F scale which ranges the usual outdoor temps seems to be more practical. Using temperature scales as an example or counterexample of the metric system’s usefulness is rather a red herring - the fact that the centigrade scale imposes 100 divisions between the freezing and boiling points of water is not really anything like what the metric system is about - in fact, I’m not even sure the centigrade scale can be properly called metric - it just superficially resembles it. It’s not about division into 100 pieces, it’s about ease of conversion between small and large units. A kilogram is 1000 grammes. A metre is 1000 millimetres. A litre is 1000 millilitres. Any work done on metric measurements is simple mathematics performed on a single measurement value in a single number base. The same isn’t usually true of non-metric measures - they are often composed of a collection of different measurements in different bases - for example, a measurement in feet, inches and eighths - try performing division on such a composite value - it’s definitely harder than doing an equivalent division on single decimal value. ---
**Author:** ![Canadjun](https://avatars.discourse-cdn.com/v4/letter/c/76d3ee/32.png) [@Canadjun](https://boards.straightdope.com/u/Canadjun)\ **Post date:** [October 20, 2009, 10:39pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/93 "2009-10-20T22:39:12Z")
> [@TBG](#): > > On the other hand, some American measurements are actually better than metric. Take the foot. You can get an EXACT measurement for a third of a foot. 4 inches. What’s a third of a meter? .33333333333333repeatuntilinfinity meters. Oh, slightly less precise, but hey, at least divide by ten comes out to exactly .1 meter! Then again, that’s no more precise than .1 foot or 1.2 inches… The fact that mathematically you’ll get a repeating decimal is irrelevant in real life. Use the precision appropriate to whatever you are doing. For all \*\*practical \*\*purposes a third of a meter is .333 meters (or 33.3 centimeters or 333 millimeters). ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 20, 2009, 10:40pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/94 "2009-10-20T22:40:05Z")
> [@TBG](#): > > On the other hand, some American measurements are actually better than metric. Take the foot. You can get an EXACT measurement for a third of a foot. 4 inches. What’s a third of a meter? .33333333333333repeatuntilinfinity meters. Oh, slightly less precise, but hey, at least divide by ten comes out to exactly .1 meter! Then again, that’s no more precise than .1 foot or 1.2 inches… This is mostly a specious argument - sure, 10 doesn’t exactly divide by three, but twelve doesn’t exactly divide by 5. Yes, 12 has more factors, but that’s only useful if you want to do integer maths using a value that happens to be one of those factors. And people don’t _use_ decimal parts of a foot - they use inches - and there are twelve of them. Nobody says “0.1 feet” - and if they did, it how would that weaken the argument that working with single values in base 10 is easier. I’m aware that there are decimal divisions of inches in use in various places, but I’ve never physically seen a measuring device featuring them - it’s all eighths. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 20, 2009, 11:20pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/95 "2009-10-20T23:20:18Z")
> [@](#): > > Oh, slightly less precise, but hey, at least divide by ten comes out to exactly .1 meter! Then again, that’s no more precise than .1 foot or 1.2 inches… By the same token, sure, you can talk about 1/3 of a foot, but you can also talk about 1/3 of a meter. You don’t need any decimal places at all; just say “one third of a meter”. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [October 20, 2009, 11:30pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/96 "2009-10-20T23:30:03Z")
> [@Mangetout](#): > > I’m aware that there are decimal divisions of inches in use in various places, but I’ve never physically seen a measuring device featuring them - it’s all eighths. depth of snow is measured with a stick with tenths of inches. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 20, 2009, 11:31pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/97 "2009-10-20T23:31:50Z")
I’ve never seen such an animal, but then it seldom snows here and when it does, I’ve never seen anyone measure it. I’m guessing there are not ten of these inches to the foot though… ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [October 21, 2009, 1:59pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/98 "2009-10-21T13:59:29Z")
Regarding fuel economy measures in car adverts, here in the UK almost all adverts seem to give both mpg and litres/100km. But what bugs me is that the metric measurements are “back to front” compared with the imperial ones. X mpg means I will get X miles per 1 gallon of fuel. Larger X is good. X litres/100km means in order to go 100km I will need X litres of fuel. Larger X is bad. Why the hell not “kilometres per litre”? Were they worried the numbers would come out too small? 35 mpg (using imperial gallons) comes out to about 12.4 km/litre. That seems sensible. So why do they instead quote it as 8.1 litres/100km? And how many people in Dumb Britain actually realise that a smaller number is better under this system, I wonder? 😉 Thank heaven for [Google](http://www.google.co.uk/search?hl=en&safe=off&c2coff=1&q=35+miles%2Fimperial+gal+in+litres%2F100km&meta=&aq=f&oq=)! ---
**Author:** ![Mk\_VII](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@Mk\_VII](https://boards.straightdope.com/u/Mk_VII)\ **Post date:** [October 21, 2009, 2:28pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/99 "2009-10-21T14:28:24Z")
because kilometres travelled per litre consumed would be so small that people would be scratching their heads over fractions - another instance of the impracticality of many SI quantities (farads, anyone?) . ---
**Author:** ![garygnu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garygnu/32/2924_2.png) [@garygnu](https://boards.straightdope.com/u/garygnu)\ **Post date:** [October 21, 2009, 2:52pm UTC](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126/100 "2009-10-21T14:52:50Z")
> [@johnpost](#): > > depth of snow is measured with a stick with tenths of inches. At a picture frame shop I worked at, we had a ruler that had inches divided into tenths. Why we had it I don’t know, maybe to keep us on our toes. [Previous page](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126.md?page=4) [Next page](https://boards.straightdope.com/t/the-united-states-and-the-metric-system/514126.md?page=6)