A kilogram (also known as a kilo) is a unit of weight in the metric
system equal to 1000 grams. One gram is equal to about .035
ounces. This means that you need 28.3 grams to get one ounce.
There are 16 ounces in one pound. That means that you need
453.36 grams just to get one pound. One kilogram is equal to
2.2046226 pounds. A kilogram is also equal to the mass of about
one liter of water.

FEATURED BOOK: Oxford Dictionary of Weights, Measures,
and Units
Kilograms came into use because trade and commerce usually involved items that were
much greater in weight than one gram. To create a standard, a single metallic artifact
was made that was 1000 times heavier than the gram. This was called the kilogram. The
artifact was made of metal (90% platinum, 10% iridium) as opposed to water (a prior
standard) because it was instable and not convenient. The artifact is known as the IPK
(International Prototype Kilogram). Three versions were created in 1979 and are stored
in secure vaults in Paris. It was formally designated as the kilogram in 1889 by the
General Conference on Weights and Measures.

The word "kilogram" is commonly abbreviated as kg. Kilogram comes from the Greek
word "chilioi" meaning "thousand," and the Latin word "gramma," meaning "small weight."
Put the two words together and you have a "thousand small weights."
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