Loading...
Loading...
Convert kilograms, grams, pounds, ounces, stones, and metric tonnes instantly. All calculations run in your browser.
Technically, kilograms measure mass, not weight. Weight is a force equal to mass multiplied by gravitational acceleration (W = mg). On Earth at sea level, a 1 kg mass weighs about 9.81 newtons. In everyday use, however, "weight" and "mass" are treated as synonyms, and the units on this page cover both the metric and US/UK systems that people encounter daily.
The kilogram is the SI base unit of mass. One kilogram equals 1,000 grams. A metric tonne equals 1,000 kilograms. These clean decimal relationships make metric calculations predictable: a recipe that calls for 250 g of flour is simply a quarter of a kilogram.
The US and UK systems use pounds and ounces. One pound equals 16 ounces. The international avoirdupois pound is defined exactly as 0.45359237 kilograms, which gives 1 kg = 2.20462 lbs. Ounces are common in US cooking and in jewellery, though jewellery uses the troy ounce, which is heavier than the avoirdupois ounce at 31.1035 g versus 28.3495 g.
The stone is a unit unique to the UK and Ireland, still widely used for measuring body weight. One stone equals exactly 14 pounds. A person who weighs 11 stone 4 lbs weighs 158 lbs or about 71.7 kg. Outside the UK, this unit is rarely seen, which makes it a frequent source of confusion for international travellers.
Shipping carriers charge by weight or volumetric weight, whichever is greater, in kilograms for international freight and pounds for US domestic ground services. Getting the conversion wrong can mean unexpected surcharges at the depot.
In medicine, drug dosages are calculated per kilogram of body weight. A paediatric dose of 10 mg/kg for a 30-pound child requires converting 30 lbs to 13.6 kg before the calculation can begin. Errors in this step have clinical consequences, so the conversion must be exact.
In cooking, US recipes list butter in sticks (4 oz each) while UK recipes use grams. A stick of butter is 113 g. Knowing that 1 oz = 28.3495 g lets you scale any recipe across systems without guessing.
How many pounds are in a kilogram?
One kilogram equals approximately 2.20462 pounds. The exact definition is 1 lb = 0.45359237 kg, so 1 kg = 1/0.45359237 lbs.
What is a stone in kilograms?
One stone equals 14 pounds, which is approximately 6.35029 kilograms. The stone is still used for body weight in the UK and Ireland but is not recognised as an SI unit.
Is a metric tonne the same as a US ton?
No. A metric tonne is 1,000 kg (about 2,204.6 lbs). A US short ton is 2,000 lbs (about 907.2 kg). A UK long ton is 2,240 lbs (about 1,016 kg). Always specify which tonne you mean when working across systems.