Weight Converter
Convert any weight or mass between metric and imperial units, including the stone and the three different tons, with the exact factor shown.
How it works
Weights here are defined against the kilogram. The pound is exactly 0.45359237 kg by international agreement, so metric and imperial weights convert exactly rather than approximately.
Strictly, weight and mass are different things — mass is how much matter there is, weight is the force gravity exerts on it. In everyday use the words are interchangeable because gravity is near enough constant on Earth, and that is the sense used here.
The stone is 14 pounds and is still used for body weight in Britain and Ireland. Watch the tons: a US short ton is 2,000 lb, a UK long ton is 2,240 lb, and a metric tonne is 1,000 kg. All three appear on shipping documents.
The formula
kg → lb
lb = kg × 2.2046
lb → kg
kg = lb ÷ 2.2046
Any pair in this family
result = value × (factor of source ÷ factor of target)
Every unit is defined against the kg, so any combination converts in one step.
Worked examples
| Scenario | Working | Result |
|---|---|---|
| 1 kg to pounds | 1 ÷ 0.45359237 | 2.2046 lb |
| 70 kg to stone | 70 ÷ 6.35029 | 11.02 st |
| 1 metric tonne to US tons | 1000 ÷ 907.185 | 1.1023 short tons |
When you'd use it
- Converting body weight between kg, pounds and stone
- Checking a baggage or freight allowance
- Following a recipe written in the other system
- Reading shipping paperwork that mixes tons and tonnes
Common questions
What is the difference between a ton and a tonne?
A metric tonne is 1,000 kg (about 2,204.6 lb). A US short ton is 2,000 lb (907.2 kg) and a UK long ton is 2,240 lb (1,016 kg). All three are offered here separately because confusing them on a shipment is expensive.
How many pounds are in a kilogram?
2.20462 pounds, from the exact definition of one pound as 0.45359237 kg. For rough mental arithmetic, doubling and adding 10% gets you within about 0.2%.
Is weight the same as mass?
Not physically — mass is constant, weight is the gravitational force on that mass and changes with location. For everyday conversions on Earth the distinction does not matter, which is why both terms appear on the same scales.
Is anything I enter sent anywhere?
No. Every conversion runs in your browser, so nothing you type is uploaded, logged or stored. There is no account and no record of what you converted.