Formula
1 lb = 0.45359237 kg (exact)1 lb = 16 oz; 1 oz = 28.349523125 g1 stone = 14 lb1 US ton = 2,000 lb; 1 tonne = 1,000 kg How it works
The avoirdupois pound is defined as exactly 0.45359237 kilograms, so pounds and kilograms convert precisely: multiply pounds by 0.4536 for kilograms, or kilograms by 2.2046 for pounds.
Since 2019 the kilogram has been defined through the Planck constant rather than a metal cylinder in Paris, but nothing changed for everyday conversions. Grams and milligrams are simply thousandths and millionths of a kilogram.
Three different “tons” are in use: the US short ton (2,000 lb), the UK long ton (2,240 lb) and the metric tonne (1,000 kg, about 2,205 lb). Body weight in the UK and Ireland is often quoted in stone; one stone is 14 pounds.
Frequently asked questions
How many pounds are in a kilogram?
About 2.20462 lb.
Is weight the same as mass?
Strictly, kilograms and pounds measure mass, while weight is a force. On Earth the two are used interchangeably in everyday life, and this converter follows that convention.
Are troy ounces the same as ounces?
No. Precious metals use the troy ounce of 31.1035 g, about 10% heavier than the ordinary 28.35 g ounce used here.