Weight Converter
Convert weight and mass between metric and imperial units — kilograms, grams, milligrams, tonnes, pounds, ounces and stones — with every unit shown at once.
How to use this calculator
- Enter the weight you want to convert.
- Pick the from and to units.
- Press Convert to see the answer plus your weight in every other unit.
Formula used
The pound is defined as exactly 0.45359237 kg. Stones (used for body weight in the UK and Ireland) are 14 pounds each.
Example calculation
Convert 70 kg to pounds: 70 ÷ 0.45359237 = 154.32 lb — or 11 stone 0.3 lb in UK terms.
Weight units around the world
Most of the world weighs in kilograms; the US uses pounds and ounces; the UK famously mixes both, with body weight in stones and pounds. All are linked by one exact definition: 1 lb = 0.45359237 kg.
Quick anchors: 1 kg ≈ 2.2 lb, 100 g ≈ 3.5 oz, 1 stone ≈ 6.35 kg. For cooking, note that ounces here are weight ounces — fluid ounces measure volume and live in the volume converter.
Why use this calculator?
- Convert body weight, luggage limits, cooking amounts and shipping weights instantly.
- See stones alongside kg and lbs — essential for UK contexts.
- Exact defined factors, so results survive round-tripping without drift.
Frequently asked questions
How many pounds is 1 kg?
1 kg = 2.20462 lb. The quick mental version: double the kilograms and add 10% — 70 kg → 140 + 14 = 154 lb.
What is a stone in kg?
1 stone = 14 lb = 6.35029 kg. So someone weighing 11 stone weighs about 70 kg or 154 lb.
Is weight the same as mass?
Technically no — mass is the amount of matter (kg), weight is the force gravity exerts on it. In everyday use on Earth they're used interchangeably, and these conversions follow that convention.