The CIA has an interesting page on its World Factbook website, with all imaginable Weights and Measures conversions.


Here, besides the usual conversions, such as:

  • 1 cubic foot is just over 28.3 liters
  • 1 kilogram is about 2.2 pounds

you will learn obscure facts, for example:

  • 1 bushel is 4 pecks
  • 1 dram is 60 minims
  • 1 gill is about 0.03 gallon
  • 1 grain is about 0.05 scruple

Hmm… very interesting indeed. 

But what the heck are those weird units, and who exactly uses them nowadays when the SI (Système International d’Unités, International System of Units or Metric System) has been in use since 1948 and published in 1960, and provides a coherent systems of units of measurements. Its seven base units are:

  • meter for length
  • kilogram for mass
  • second for time
  • ampere for electric current
  • kelvin for temperature
  • candela for luminous intensity
  • mole for amount of substance 

Derived units such as hertz, radian, newton, pascal, joule, watt, volt, ohm or lumen provide a clear, internationally accepted framework where calculations are simplified by the absence of conversion.


However, as indicated on the CIA website: “At this time, only three countries – Burma, Liberia, and the US – have not adopted the International System of Units (SI, or metric system) as their official system of weights and measures. Although use of the metric system has been sanctioned by law in the US since 1866, it has been slow in displacing the American adaptation of the British Imperial System known as the US Customary System. The US is the only industrialized nation that does not mainly use the metric system in its commercial and standards activities, but there is increasing acceptance in science, medicine, government, and many sectors of industry.” 

Only THREE countries, and the US is one of them 🙁


In a well-known story, “NASA lost a $125 million Mars orbiter in 1999 because a Lockheed Martin engineering team used English units of measurement while the agency’s team used the more conventional metric system for a key spacecraft operation“, according to this CNN article.

For more fun reading, there is an article on Ken Butcher, who used to be the only employee of the Metric Program in Washington (they are now two) although the Metric Conversion Act has been signed into law by President Gerald Ford in 1975. Go figure!

I wonder how much longer it will take for the US to join the rest of the world on this.