America is one of only 2 countries in the world (the other is a very small country) that do not use the metric system. The metric system is far superior..Americans do use it in their monetary system and I have seen Kilometer per hour speed limits in Arizona..but I have no idea why they haven't converted..It is a massive project to be sure..but I think that it is far superior (I grew up on a non metric system in Canada --but we switched years ago).

Because if they switched to metric, the famous "Royale with cheese" exchange in The Big Lebowski would no longer make sense. :P

I was brought up with feet and inches,pounds and ounces then went metric a number of years back and i still use feet and inches,pounds and ounces.The road signs here in the UK are still in miles and not kilometers so whats that all about.

Because we're dumb.

"The current effort toward national metrication is based on the claim that industrial and commercial productivity, mathematics and science education, and the competitiveness of U.S. products and services in world markets would be enhanced by completing the change to the international standard measurement system based on metric units. Many or most Americans, however, remain unconvinced of this position, or disagree over whether and how to pay and enforce complete conversion, which, if undertaken, could possibly incur considerable expense in the near term for millions of businesses and government agencies. A potential problem for current metrication efforts is that many or most U.S. citizens, thirty years after the 1970s metric push, have little interest in metric usage. Daily life no longer features even dual usage of units such as Celsius for temperature, so most Americans have little contact with metric units on a daily basis. Those who need to use the metric system for work learn it, those who travel overseas learn enough to get by, but most others do not feel generally compelled to use it." Source and further information: http://en.wikipedia.org/wiki/Metrication_in_the_United_States

Because the US thinks they're better than everybody else and is too "cool" for the silly metric system. Psh, they should just change to metric already.

Short version? There's people that are USED to the version we used now. To stop everything and just CHANGE it would be difficult. Including those that are in college and high school. So transition Oh, and like more ppl we resent change

We tried to convert in the 1970's. People did not take to it because they were too comfortable with the old system.

I`m a Russian woman, living in Russia, and it`s rather difficult for me to understand your system, and the time- p m, a m ,and also the temperature.

Because they're being silly : P hehe Metric is MUCH better, MUCH more efficient, and MUCH easier... It's just a difficult task to convert unfortunately... They're getting there slowly though, their money system is metric, their... uh... bullet calibres are mostly metric... And maybe something else, lol : P Seriously, just about every other country in the world has made the change, but the US in all it's economic, technological, and military superiority can't seem to manage switching over : / (or just plain doesn't want to, which confuses me.)

Firstly they are not the only country to not use the metric system. The UK also still uses the imperial system, although it is used less and less often with each passing day and the UK system is slightly different from the US system. Secondly, I see on other comment threads you claim metric to be more accurate, it is not! The metric system is far superior to any imperial system as we count using a decimal based numerical system so out brains are used to factors of 10. The US is not switching over to metric basically because a high proportion of its population are unable to think in anything other than the imperial system that took them so many years to learn. Their education system is in desperate need of a huge shake-up and hopefully this will happen soon, including introducing the metric system to the children, maybe only teaching metric (like they did in the UK 15 years ago), the switch will take time, but they should switch soon, hopefully.

America DOES use the metric system, we just do not use it exclusively or even predominantly. The metric system IS taught in the school systems, and is required. All sciences are taught using the metric system. Milk comes in gallons, but we buy 2 and 3 liter bottles of soda, for instance. We are not the only country to still use the imperial system in some manner. http://en.wikipedia.org/wiki/Metrication_in_the_United_States

more or less this: Both the Imperial system and the USA system of measurement are based on the older English units of measurement. Prior to 1066 the English units included Anglo-Saxon measures (likely of ancient Germanic origin). After the Norman conquest (Battle of Hastings in 1066), the Normans re-introduced Roman measures, resulting in a system including ancient Anglo-Saxon measures and Roman measures. These units were standardised by the Magna Carta of 1215 and were periodically reviewed and updated (notably in 1496, 1588 and 1758). The UK Weights and Measures Act of 1824 was one such review, which not only modified the types and sizes of the units, but renamed them from the English units of measurement to the Imperial System of Measurement. This new standard was then introduced throughout the UK and its colonies at this time. However, the USA had become independent prior to this and consequently did not adopt the Imperial system of measurement. Instead, they had developed their own measurement standards, based on the English units system which was used throughout the States prior to independence. As a result, the older English units developed into the USA system of measurement in the USA and into the Imperial system of measurement in the UK and countries colonised by the UK. basically we got it from the English... then split, and thus we did not stick to their system, like other colonies. NOT because we think we are better but it's just what you are use to. Although I do like the metric system a lot!!! I hope the switch comes soon. BUT the cost to replace the road signs alone would be huge!

For me, it is simply so much easier to say, for example, 1 cup rather than 236.588 ml. "Then add two hundred thirty six point five eight eight milliliters of sugar" For everyday usage it is just easier. But the metric system IS used a lot in some areas, such as the medical field. Drug dealers seem to use it quite a bit as well..gram..kilo..etc.

1) Early colonists to America used European weights and measures, many of which were initially based on odd things like the length of the king's arm, foot, stride etc. By the 18th Cent most of this was becoming standardised to aid trade and early science. 2) The metric system popped up just a little too late for the fledgling USA & due to various pushes in continental Europe from around 1790-1840 the metric system was encouraged against the "Imperial" system favoured by the British which in so many ways is utter bonkers. The US Govt did in fact pass laws in the mid 19th Cent to allow the use of metric measures - a missed opportunity perhaps? I went through the imperial-metric conversion process in primary school in the 70s and it all seemed pretty straightforward, with a few downsides: - the teachers struggled to get their heads around it - weights were the hardest to come to terms with when almost all weights in real life situations were still imperial. You can see a metre but you can't "see" a kilogram or a stone... There's not much difficulty with keeping a few imperial measures - pints and miles still mean so much to so many people it seems silly to get rid of them. Although I still measure myself in feet and stone I can mentally convert them to a rough metric equivalent. I'm sooooo glad the UK went metric - I really feel sorry for my parents who had to deal with mad measures as well as the completely insane pounds shillings and pence (a base-12 monetary system for heaven's sake!).

There isn't any such thing as an "American Standard" system of units. The National Institute of Standards, NIST is not a government organization. It is private and it sets standards for manufacturers in this country in both Metric and Imperial units. I am guessing that the units that you are speaking of are things like foot, gallon, etc. These are correctly called "Imperial units" and they are a gift from our "mother country", England. From those basic imperial units, we have built more complex units like foot-pound, which are called English Engineering Units. Beginning with the Industrial Revolution and continuing to the present day, machine tools and consumer goods are made using standard units, because they need to work with the items that people already own. People around the world build things in Imperial units because they want to sell them in one of the world's biggest markets, the USA.

After winning two world wars, the USA became full of itself. The USA had no reason to import or export anything, the GNP being the highest in the world, etc, we felt like we were better than everyone else. The USA is too vain or lazy-minded to convert.