Photo from iruler.net.

This one goes out mainly to my fellow Americans (sounds presidential, huh?). As an American, born and bred, I grew up utilizing several measurement systems that nobody else in the world seems to understand. It’s not my fault; I wasn’t in charge of the curriculum which I was taught from. However, what would be my fault, especially as a traveler, is to not acknowledge the fact that virtually no other country utilizes the systems I know, as well as to not try to learn at least the basics of said systems.

Metric vs. Imperial

Let’s start with the metric system vs. the imperial system. The imperial system (also known as the system of imperial units or British Imperial) was started by the British back in 1824 with their Weights and Measures Act, and it quickly spread throughout the entire British empire, as well as to other parts of the world. However, metrication (the act of converting other measurement systems to the metric system) has swept virtually the entire globe, even with Canada, Australia, and the U.K. using it more than imperial. The only industrialized nation to still use it is the U.S., which means that Americans are behind, so to speak. We are a stubborn breed, I guess, but we should definitely learn the basics of how to convert and some general equivalencies should be memorized, perhaps. Below are some standard conversions:

Imperial Metric
1 inch [in] 2.54 cm
1 foot [ft] 12 in 0.3048 m
1 yard [yd] 3 ft 0.9144 m
1 mile 1760 yd 1.6093 km
1 int nautical mile 2025.4 yd 1.853 km
Imperial Metric
1 sq inch [in2] 6.4516 cm2
1 sq foot [sq ft] 144 in2 0.0929 m2
1 sq yd [yd2] 9 sq ft 0.8361 m2
1 acre 4840 yd2 4046.9 m2
1 sq mile [mile2] 640 acres 2.59 km2
Imperial Metric
1 cu inch [in3] 16.387 cm3
1 cu foot [ft3] 1,728 in3 0.0283 m3
1 fluid ounce [fl oz] 28.413 ml
1 pint [pt] 20 fl oz 0.5683 l
1 gallon [gal] 8 pt 4.5461 l
Imperial Metric
1 ounce [oz] 437.5 grain 28.35 g
1 pound [lb] 16 oz 0.4536 kg
1 stone 14 lb 6.3503 kg
1 hundredweight [cwt] 112 lb 50.802 kg
1 long ton (uk) 20 cwt 1.016 t

Fahrenheit vs. Celsius

Though most countries used to use the Fahrenheit system to measure temperatures, Celsius, or Centigrade, was adopted worldwide in the 20th century. Fahrenheit remains the official scale of the United States, Cayman Islands and Belize only, so you can see why travelers should take note of the Celsius system and know how to convert from one to the other. Even the U.S. military uses Celsius!

Here’s the formula to convert Fahrenheit to Celsius and back:

C -> F

1. Take the temperature in Celsius and multiply 1.8.

2. Add 32 degrees.

F -> C

1. Take temp in Fahrenheit and subtract 32.

2. Divide the value by 1.8

Time

Time in the U.S is on the 12-hour clock, while most of the world uses 24-hour time, without the need to designate between a.m. and p.m. Again, even the U.S. military uses 24-hour time, but Americans prefer to call that “military time”.

It is not difficult to decipher 24-hour time, just subtract 12 from any number greater than 12 and it will be that time in the p.m.

21:00 is 9:00pm – Simple!

Dating Systems

Americans seem to organize dates differently from everyone else too, as if we haven’t already annoyed the rest of the world enough. Most of the world uses Gregorian little-endian, starting with day then going up (Day-Month-Year):

4 August 2012 or 4/8/2012 or 04.08.12

However, Americans use a system which makes no logical sense, called middle-endian; it goes month, followed by day, then followed by year:

August 4, 2012 or 8/4/2012

Having a world with two different standards can be confusing, so it is best to remember that most of the world puts the day first!

Other Differences

There are many other differences that may make Americans look like isolationists who don’t care about universal standards. American English differs substantially from British English in spelling and pronunciation, though both are acceptable. Most common are the American English use of “z’s” rather than “s’s” and the dropping of the “u” in words like “colour”.

Of course there is the electrical differences, but there are less universal standards for electrical outlets throughout the world.

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