Weight & Mass Converter

Metric, imperial, and US customary units, converted both ways.

 

Common conversions

Weight & mass unit reference

What 1 kilogram equals in every other unit.

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Why a "ton" isn't always the same weight

Ounces and pounds mean the same thing whether you call them "imperial" or "US customary" — a pound is a pound on both sides of the Atlantic. Tons are where the two systems genuinely part ways.

The US short ton (used in the United States) equals 2,000 pounds, or about 907.18 kg. The UK long ton (the traditional British imperial ton, still referenced in some shipping and industrial contexts) equals 2,240 pounds, or about 1,016.05 kg — roughly 12% heavier. Neither of these is the same as the metric tonne (1,000 kg exactly, also written "metric ton"), which happens to sit almost exactly between the two: close enough to a US ton to cause real confusion in international trade and shipping documents, but not identical to either.

A related unit, the stone (14 pounds, about 6.35 kg), is still the everyday way body weight is expressed in the UK and Ireland, but it isn't used for general commercial weighing the way pounds and kilograms are.

1 US short ton = 2,000 lb  ·  1 UK long ton = 2,240 lb  ·  1 metric tonne = 1,000 kg ≈ 2,204.6 lb