Let's have a look what supporters of the English Imperial system have to say and why it's all nonsense:

We have a perfectly good measuring system, so why does the USA have to change to using the metric system?

No, we don't have a perfectly good measuring system! We have a clumsy, entangled, confusing measuring system! And it not only confuses the rest of the world - no, it perplexes Americans themselves!

If you go to buy carpeting, and you need 100 square feet, the carpet costs $10 per square yard, could you, even given these simple numbers, ever figure out how much you'll pay? Which is more, 2 quarts, 5 pints or 36 fl oz? How many pints are in a gallon? How many pounds are 200 ounces? Which drill is the larger - the 13/64, the 1/4 or the 5/32? Two cities on a map are 10 inches apart - what is their real world distance?

Do you have to default on these questions? Then you have a problem - a problem called English Imperial system.

But the English system represents our culture and traditions, it's our heritage - we can't give it up!

First of all - the English system is not American - it's English! So on which cultural grounds are you claiming something English as American heritage while you reject something French as alien?

In fact, a large part of American culture is actually European culture, not only is the measuring system, but also language, religion, architecture etc. Sure did Americans tweak this heritage, but the essence stays European. On the other hand, many innovations are originally American, like much modern technology, music culture, and life-style - and these are truly to be proud of. The English system though is definitely not among them - it's not American, and it's not to be proud of either.

The world is continuously changing, and humans are ceaselessly improving their living conditions. That includes getting rid of old, stupid procedures and habits, and acquiring new, more intelligent procedures and habits.

Don't you think it caused a hell of a protest each time the English system 'evolved'? When all the slightly different feet were unified in one standard foot, all the pounds in one pound, all the various gallons in one gallon. How many beloved medieval units had to go and how many Englishmen were plunged into an identity crisis to make room for what is now called English system!

Culture and traditions of the U.S. as a young country were always evolving and changing - they were defined and are maintained and represented by the people who live here. Now it is time to define a new part of culture. Would you really stick with a stupid habit just because you always did it such a way? Would you continue to use a horse cart instead of a van just to honor your grandfather who always used one? Would you dig a well in your garden instead of having running water just because that's where all your ancestors got their water from? Can you be truly proud of something that is silly?

And, most importantly, would you not take some good advice just because it was not your idea? Would you be a fool for the sake of being different? Is that American pride or American folly?

Be proud of the constitution, the Space Shuttle, the Internet, the Pentium processor, but - please - don't be proud of the English system.

The rest of the world imposes the metric system on us!

No, other countries are just going to refuse import of goods that are not to metric specification. This is every country's free choice, and in fact the U.S. 'impose' all kind of specifications on its imports, too. The U.S. even impose sanctions on other countries which export to other countries, like Cuba or Iraq! Might you find this rightful or not, it's compulsory and by no means democratic.

The rest of the world made the free decision to adopt the metric system while the U.S. decided to stay with the English Imperial system. Had the U.S. started to convert early, would there be neither significant costs nor difficulties. Now though, that the world is moving on but we chose stagnation, we are facing the consequences.

In the 1980s Japanese cars became increasingly popular, simply because they were the better product, and sale of U.S. cars declined because people just won't buy crap only because it's American. Fortunately the U.S. automotive industry understood, and the result is even better cars. Applying dogmatic traditions and blind vanity to a progressive economy just doesn't work.

Why should we switch to metric just because all other countries did?

Right, we should not switch to metric just because all other countries did - we should switch because the metric system is the better system! Because science, education and business have already and will profit more from the better system in the long run. Ask scientists, engineers, teachers! Don't ask those who consider our system of measurement an instrument of pride, while it's really only an instrument of measurement.

This discussion is often confused with a battle English against metric, with a struggle of two fanatics for world domination. Power was never the aim of the metric system's fathers and advocates. The goal was from the very beginning to establish a simple, easily used system of weights and measures to simplify international trade and scientific research. Is it a minority complex or a rebellion without a cause that makes some Americans turn this technicality into a crusade?

After all not all other countries switched to metric!

Well, except for the rest of the world two third world countries haven't officially committed to the metric system: Liberia and Burma. But they already use metric units all over the place and are well on way leaving the sinking Imperial ship. So who's going to get wet?

America became the great country it is using the English system!

How about: America became the great country it is despite using the English system! And it could be an even greater country without it!

American units naturally evolved, while metric units were arbitrarily defined.

Oh come on, at some point in time, every unit on this planet was arbitrarily defined by someone. Regardless if referencing human feet or the earth's circumference.

In metricated countries, non-SI metric units live on, because they are more useful, like the centimeter, or the French quintal.

First of all, the centimeter is a valid SI unit, and actually many other metric units, though not recommended by SI, are allowed nevertheless, like bar, hectare and ton. Yes, the quintal, though metric, is not allowed under SI. However, all of these units can be scaled to SI units by powers of 10, i.e. just by shifting the decimal point (1 bar = 100,000 pascal, 1 hectare = 10,000 m², 1 ton = 1,000 kg, 1 quintal = 100kg). Also, all non-metric units have been redefined to exact metric values, e.g. 1 pound = 500g, 1 pint = 500ml. And, even though not strictly part of SI, these units are metric and do not constitute a contradiction to its philosophy.

Some non-metric units though, like the horsepower, are still around for completely irrational reasons. E.g. in metric the power of a car is specified in kilowatts, like 85kW. However, the same power in hp (114hp) sounds more. Therefore, to impress naïve customers, European car dealers tend to supply translations of their cars' power to hp!

After all, the SI system is a standard for science and trade, not a tool to oppress people as you like to view it. Everyone can in their private life measure any way they like.

And you are applying in an unfair way different scales to both systems: You picture the English system as the system of the people, the metric system as the system of the bureaucrats. This is simply not true. To reduce the medieval hodgepodge of gazillions of similar, but still not quite equal units into the at least somewhat usable nowadays English system did sure require major bureaucratic interventions. And common people all over the world have used the metric system for generations and like it. Yes, like it.

Look at definition and use of each system separately. It's not that the English system is just used, while the metric system is only defined. Both systems are both defined and used, and the metric system is truly superior in both definition and use.

Many metric countries even still use English Imperial units.

Still is the right word. There are a few traditions which are very deeply established. While thousands of other things are measured in metric units, for example tires and pressure plumbing are manufactured to imperial specifications throughout Europe. In fact, you can buy plumbing supplies in Europe and they will fit here. But — the so-called inch pipe names are nominal numbers that do not reflect an actual size. There is nothing 1/2 inch about a half-inch pipe. In fact there are different standards for pipe sizes depending on whether it is water pipe, gas pipe, or electrical conduit. Half-inch water pipe is really 16 mm inside diameter and 18 mm outside diameter. Neither of these comes close to 1/2 inch.

And after all even these are dying standards based on outdated traditions. In the automotive industry (even U.S. companies), imperial parts are step by step replaced by metric parts. Will the plumbing or tire industries experience paradigm shifts in the future (and they will for sure, e.g. polymer plumbing), the new technology will be for sure to metric specifications. And — since imperial units are officially defined in terms of metric units, everything to imperial specification is automatically and inevitably to metric specification anyway.

After all the U.S. economy, per capita, is bigger than the EU's and the U.S. has a greater role in world trade and politics.

1. Actually Luxembourg has the world's highest GDP (Gross Domestic Product) per capita, so let's Luxembourg (an EU member!) decide.
2. To measure the total economical power, you have to consider the total GDP. And currently, we can very well talk about equal powers here. The U.S. (9192.0 B$) outweighs the EU (8487.8 B$) only marginally, and already only OECD Europe (9349.7 B$) is economically stronger than the U.S.. Not to mention the rest of the metric world like Japan (4320.2 B$). (data for 1999 from oecd.org)
3. Sure does the U.S. as a single country have the strongest economy and the strongest military in the world. This enables the U.S. to take an important role in economics and politics. However, since long ago world economy and world politics is not about single countries any more. And this role is not a position assigned by other nations, but self-assumed. There is nothing bad about this, except that any right you deduce from this fact is again self-assumed. With other words, a statement based on an opinion stays an opinion. Let's try to impose the English system on the rest of the world and see what happens!

The French people did not readily take to the metric system.

People in general do not readily like anything new, regardless of its usefulness. This common detest of change does not in any way disprove its usefulness.

In fact, wouldn't you agree that all the many changes that America underwent on its way from a 17th century British colony to nowadays progressive nation were in fact seldomly welcomed?

Every innovation, every bit of progress had to survive the malicious resistance of outdated people pretending to preserve traditions but only hampering progress and prosperity.

The introduction of the metric system does not undergo a democratic process. Who ever asked the American people if they want to have part of their culture erased by metricators?

The U.S. have a so-called representative democracy. Decisions are not made by the people, but by representatives elected by the people. These representatives then make laws, decide if to engage in war with other countries, or if to update weights and measures. If you wanted a public ballot on the metric system, you would have to question how democracy works in the U.S. in general, and that is a whole different topic.

The metric system in the U.S. has spread through the lobbying and implementation efforts of bureaucrats, technocrats and other individuals and bodies not representative of the majority of the population.

Well, bureaucrats and "technocrats" are appointed through elected federal, state or city governments, and are therefore in fact representing the majority of the population. We could engage in discussion how democratic U.S. democracy really is, but that is not a problem of the metric system.

Other individuals and bodies put up their web sites, making use of their right of free speech, and never claimed themselves representatives of the majority of the population!

The European Commission is forcing metric units on the UK by prohibiting traditional units. No Brit ever asked them to do so.

First of all, the UK decided to adopt the metric system out of their own free will, and well before they joined the EU. The trouble with the EU government came about only because the conversion process went ahead rather slowly. And then, after all, a union always means compromise. You cannot expect to only benefit from a union and never give in. If the British never wanted to compromise on any of their traditional values, they would have better never joined the EU. And adopting a new system of measurement consequently means abolishment of the old system, otherwise we would not gain anything except even more confusion, right?

How about the U.S. federal government forcing all kind of directives on the individual states? Why is no one complaining that the federal Supreme Court can outrule (and does) any state court?

We can do everything with the English system - we don't need the metric system!

No - we can't! First of all — the English units fail to cover enough of range for many modern measurements, like wavelength of light, mass of bloodcells etc., so metric units have to be used! Also there are many quantities that the English system does not cover at all, like electricity, magnetism, radiation!

And, what's the main point, do you know what the exact, official U.S. definition of inch, pound and gallon is since 1959? Now listen:

• 1 inch = 25.4 millimeters
• 1 pound = 453.592 37 grams
• 1 gallon = 3.785 411 784 liters

Yes: All the English Imperial units are actually defined by metric units! The English system is just a tumor on the metric system!

This means that American units are as standardized and as accurate as any metric unit!

No, it means that the American (English) units need the metric system to be good for anything accurate! The argument: "The English system is accurate because the metric system is accurate" is not really an argument for it, is it?

Boeings and Space Shuttles can be made using English units.

Better say: They can be made despite using English units! And they could be made even easier using metric units. In fact you should pay special tribute to our scientists being able to build planes and spacecraft using such a convoluted system of measurement.

As a side note, Werner von Braun, the father of NASA, loathed imperial/English units and never used them. He designed in metric and other engineers converted his units to non-metric to build the rockets. Also, Russians have ever since used metric and, as maybe few of us know, beat us in about every space milestone: First object in space, first animal in space, first man in space, first woman in space, first spacecraft on the moon, longest stay in space, etc. - except for the first man on the moon certainly. Actually, NASA finally is since 1991 required to use metric wherever possible, however this has obviously not been taken seriously enough, as NASA recently (Sept 1999) crashed a space probe due to metric/imperial conversion flaws. Since then, metric usage has been "re-assessed", but it might take a few more crashes until they will finally decide to completely switch to metric.

American units are easier to use, as they produce handier (smaller) numbers, e.g. in carpentry. Also, I rather say I am 6 feet tall than 183cm.

1. Ok, admitted - inches may be slightly handier for carpentry than centimeters or even millimeters. For every of the gazillion things you would need to measure length for you could design your own optimal unit. But that is where the confusion starts - when you measure the same physical quantity differently depending on its usage and assume that you will never have to convert units between applications.
2. For almost any English unit you will find metric units which are either bigger or smaller — and which are therefore either more accurate and produce more figures, or are less accurate and produce less figures, and vice versa. So how about feet and meters? Isn't a lot size of 480m² handier than 5167ft², or the height of a bridge of 5m as opposed to 16ft 5in? And what if you happen not to be exactly 6 feet tall, but 5'11" - is that so much handier than 180cm or spoken: 1-80?

Since the size of a degree Fahrenheit is smaller that that of a degree Celsius, Fahrenheit is more accurate!

First of all you are really arguing against yourself here. You can't say on one hand that the centimeter is less handy than the inch because it's smaller, so measurements result in larger numbers — and on the other hand turn that same vice into a virtue when the degree Fahrenheit being smaller than the degree Celsius is handier because measurements are more accurate. Sure, smaller units allow more accurate measurements, and larger units smaller numbers, but this is not an exclusive quality of either system.

Second, there is a big difference between accuracy and resolution. Because a scale can resolve to a smaller degree, does not automatically make it more accurate, especially if the media being measured does not produce stable readings in the range of that resolution.

After all, on most Fahrenheit thermometers there is a graduation every 2 degrees, while on a Celsius thermometer there is a graduation every 1°C = 1.8°F. Therefore the Celsius thermometer by that argument is the more accurate!

Under SI, water freezes at 273.16 K — even more impractical than 32°F!

Sure. Or at 0 degrees Celsius, which is also a valid SI unit. And for any temperature scale you can always find lots of freezing or boiling points that result not in whole numbers. Kelvin is basically Celsius offset by -273.15, so that 0K denotes absolute zero, the lowest possible temperatore in the universe. This makes a lot of sense for scientific calculations. The point is that in daily metric life you would use the Celsius scale, where water freezes at 0°C and boils at 100°C. This is a wonderfully practical choice for everyday life, as in northern regions the freezing point of water is of vital importance, while its boiling point is important for food preparation. Sure, gazillions of other liquids freeze and boil at quite unhandy values, but after all you have to choose some unit which makes some sense. And one wonders if on the Fahrenheit scale 0 or 100 or any number means anything or simplifies any procedure whatsoever.

Choosing a degree Celsius by subdividing the scale between freezing and boiling point of water into 100 units is utterly arbitrary.

Yes, and you know what: All units of measurement are in fact utterly arbitrary!

The base 10 system is useless, as you mostly stay within one unit and hardly need to convert between units.

1. No, you need to convert between units all the time! You measured your kitchen floor in square feet, you go to buy vinyl and they sell it by the square yard. In the supermarket, one jar tells you its contents in oz, one in quarts, another in gallons, making it a mathematical nightmare to compare prices. Real estate properties are sometimes measured in square feet, sometimes in acres (what is bigger, 150,000sqft or ½ acre?). Who is taller: 4'8" or 52"? Will the content of your 2 cu ft crate fit into a 10 gal box? There are plenty of more examples.
2. Maybe you never convert units in the English system because it's such a pain in the neck? Maybe the argument is a self-fulfilling prophecy, since who would ever dare to venture converting one English unit into another? With the English system people don't convert between units not because they wouldn't but because they can't!
3. We need to use some base to count stuff. Sure, a base 12 or base 16 system would have been probably more useful and the old Arabs were obviously narrow-minded to choose 10 as a base. But, and that's the point, all the world now uses the base 10 system, and it works — with other words, it's world heritage.

Base 12 or 16 is better than 10, as 12 divides by 2,3,4 and 6, 16 by 2,4,8 and 16, while 10 divides only by 2 and 5.

1. Ok, sure, the bigger numbers you choose, by the more other numbers you can divide them. Unfortunately for a larger base you would need a larger set of symbols, too. So are you seriously suggesting a base 12 or base 16 system? While you are defending American culture and tradition with the English system, you are asking people to give up such a tradition as the decimal system and use an arbitrary base-12 or base-16 notation for measuring? Please: Keep the decimal system, but abolish the English system!
2. How about dividing 16 by 3 or 12 by 5? The fractional beauty lasts not too far. You can always find numbers that your base does not divide by. With decimals, you can represent any number to any accuracy.
3. And after all: Base 12 or 16 would not help the English system but only make it even more convoluted! Base 12 is useful for inch-foot conversion only. For merely all other conversions it's useless! Same for base 16, which is useful maybe for oz-pound conversion, but an even greater nightmare for everything else!

Time is not measured base-10. And yet the world manages to tell time and to calculate time-related problems.

Manage is the right word! It were much easier if it used a decimal system - just people wouldn't be used to it. And, ask any scientist, when it comes to physical problems, you calculate in seconds only anyway. In astronomy, you would use sometimes d (days) or a (years) and fractions thereof in decimals. But never will you attempt any serious calculation with the common mishmash notation of years, months, days, hours, minutes and seconds.

Fractions are better than decimals because 1/3 sounds nicer than 0.33333, and "0.341 liters" looks awkward.

You are not getting here that in the metric system you never need fractions. You would not say 1/3m, you would say 33cm or 333mm, depending on how accurate you need to be. And 0.341 liters are simply 341 milliliters, a perfectly whole number.

The fractional representation in the English system makes it easy to divide values by 2,3,4,8,16 etc.!

No, it does not make it easier, because it just postpones the calculation! You write 1/2 inch, but when it comes to adding it to 5/8 inch (god save you having ever to add 1/3, 3/32 and 7/64), or simply comparing it with 7/16, you won't get around elaborate math to decide this simple question. And, worse, what if 1/64 is not enough of a subdivision? Then you have to quickly invent patches like the mil (1/1000 in - metric inspired?) to mend the hole in the inefficient system, creating dozens of arbitrarily sized units for the same physical quantity!

Also consider that fractions were devised in an era when people not only could not read or write, they could not add, subtract, multiply or divide anything complex. Also, they could not count past 20. So, the old measurement systems evolved to accommodate illiterate and innumerate peoples. We are far more educated nowadays, and capable of using intelligent systems like decimals, so why not do so?

The fractional scale of the English system uses a binary subdivision scale (1/2, 1/4, 1/8, 1/16, 1/32, 1/64). This is what computers use, too!

Computers use the binary system because it's the smallest possible base, not out of necessity to subdivide anything. Binary representation is indeed useful for binary subdivision, the same as it's silly for ternary (base-3) subdivision.

Subdividing English units is easy, e.g. half a foot is 6 inches, a quarter is 3 inches a third is 4 inches.

Sure, if you pick the one example where this works. How about half a yard, third of a pound or a gallon? Or how about a third of 7 ft 8 5/16 in given in English notation? I bet few people could even figure this out if they had a calculator!

Today we use calculators anyway, so 231 cubic inches in a gallon are as good as 1000 cubic centimeters in a liter, and using fractions is as good as using decimals.

1. Come on, you are not always carrying a calculator around.
2. To enter 17 5/16 minus 14 7/8 into a calculator is as dumb and inefficient as using this notation to begin with.
3. So, to deal with the English system, you need the help of a computer?
4. The point is not only using all the crazy conversion factors, but also remembering them. If you wanted to convert rods to inches, you would first have to remember that there are 198 inches to the rod (or 66 feet to the chain, or 231 in³ to the gallon, or 110 fathoms to the furlong, 4840 yd² to the acre etc. etc. etc.!!!) before a caclulator would be of any use! Whereas in everyday metric life, the only factors that practically occur are 10, 100 and 1000 - which are not only easy to remember, but also easy to use.

If I measure all my favorite American items in metric units, the numbers become all ugly (a quart of water becomes 0.946 liters, a 30mph speed limit becomes 48.28km/h)!

Well, Europeans just sell water in 1.0 liter bottles, and make their speed limits 50km/h instead. Just as you would define arbitrary sizes to handy values in the English system, you can do so as well in the metric system.

The naming system of the metric system is repetitive. Humans, though, find words that are distinct easier to store.

1. The metric system actually uses all distinct words for distinct concepts.
2. The repetitiveness is really an advantage. You need keep only a few units and prefixes in your mind, but can readily combine them for an abundance of handy units for any imaginable purpose, many more than you could possibly remember distinct names for. And not only that - you also understand units that you read much easier - if you encounter a unit that you have never heard of before, like kilo-newton, but you used kilo and newton before, it's a snap to figure out what a kilo-newton is. On the other hand, if there are distinct words for every unit, and you encounter a unit you never heard of before (like dram), you are without any clue.

As metric units are named abstractly, often the feel of what they mean is lost. E.g., pounds per square inch is more intuitive than pascal.

A pascal is actually nothing else than short for newton per square meter, which is also perfectly valid the metric system, and which is not less intuitive than pounds per square inch. In fact

1. newton per square meter is often preferred to pascal in scientific literature.
2. It is really more intuitive than pounds per square inch, as it clearly denotes 'force per area' as opposed to the somewhat ambiguous 'weight per area'.
3. Aren't you arguing against yourself, as you first demand that each unit have a distinct word, and then complain that a distinct word actually abstracts too much?

Traditional recipes use units such as cups, tablespoons and teaspoons. metric recipes use milliliters and grams. These abstract concepts are impractical in the kitchen.

1. Milliliters and grams are not more 'abstract' than cups and spoons. What you use is just a matter of habit. And to measure ingredients by weight instead of volume is definitely more exact, as it's independent of the substance's shape, like size of salt or sugar particles.
2. Although tablespoon and teaspoon are still quite common even in the metric kitchen, meaning 15ml and 5ml respectively, they mostly don't really save you time. If your recipe requires four tablespoons of oil, before you poured oil four times on a tablespoon, creating more a less of a mess, you are really quicker pouring 60ml of oil into a measuring cup, and from there into your dough - done.
3. And even if people all over the world use teaspoons and tablespoons in their kitchens, is that really an argument against the metric system?
4. And don't you find it a joke when a U.S. recipe demands 2 cups of margarine? Isn't it so much more fun to smear the margarine into a cup as opposed to metric recipes which demand a mass, like 250g - which you can easily obtain by cutting a 500g block of margarine in half - or, if you have such advanced technology in your kitchen - weigh it?
5. The usual metric kitchen has a measuring cup that shows not only volume, but also mass (weight) for the most common ingredients like flour, rice, sugar, salt. That way you have the choice of using the inaccurate method of measuring the amount of substance by volume - like common in the U.S., or if you are better equipped, you can always determine the mass directly by weighing.
6. And after all, recipes are for documenting a certain procedure in the kitchen as reproducible as possible. Neither system forces you to obey it exactly - it always depends on you how precisely you want to follow the instructions. And metric units give you the option to reproduce the procedure to a very high authenticity.

With the metric system one measures amounts like grain in mass (amount of matter that makes up the grain), not volume (amount of space that the grain occupies). This is unusual for Americans.

Not really! Fruits and vegetables are sold everywhere in the U.S. by mass (weight), so this whole idea is obviously not too alien to Americans. To measure mass as opposed to volume is obviously motivated by the desire to know how much actual grain one is buying as opposed to how much air in-between. And regardless, you can very well measure things by volume in metric, e.g. in m³. To reject something as bad just because it's unusual is definitely not the attitude that has made America as great as it is.

The metric system is sexist as it was created by men disregarding the needs of women.

Yes, and it is also racist, as it was created by white men disregarding the needs of colored men. We better investigate deep into the roots of the English system and find out if all those English ladies and gentlemen from whom Americans plagiarized their current system designed inch, pound and gallon with respectful regard to human rights.

How about this: The rod was originally defined as taking 16 men exiting a church on a Sunday morning and measuring their feet end to end. Why not 16 women, or 8 men and 8 women, or not exiting a buddhist temple? This is blatant sexual and religious discrimination right there!

Napoleon hated the metric system.

Now this is getting funny! You are complaining that metrication is undemocratic, and you are quoting a dictator (what could be more undemocratic)! You are protesting that metricators are forcing it on the U.S., and you are citing the establisher of the Continental System, a devastating trade war of continental Europe against British and U.S. goods, which literally ruined U.S. foreign trade!!!

Yes, Napoleon Bonaparte temporarily restored the "traditional" units (1812), after metric units had been introduced following the French Revolution (1795). But after he was given a dishonorable discharge by the British and Prussians, the metric system was again introduced (1840) and is in use ever since.

And, to quote some more respectable historic gentlemen, John Quincy Adams, Benjamin Franklin and Thomas Jefferson all loved the metric system!