Weight Converter
Strictly speaking, kilograms and pounds measure mass, while “weight” is the force of gravity on that mass — but in everyday life, everyone calls the number on the bathroom scale their weight, and so does this converter. It switches between metric (milligrams, grams, kilograms, tonnes) and imperial or US units (ounces, pounds) and also includes the stone, still used for body weight in the UK and Ireland. It is helpful for fitness and health tracking, cooking, luggage limits and shipping.
How to use the weight converter
- Type the weight you want to convert.
- Pick the starting unit (From) and the target unit (To).
- Read the result, the exact factor, and the quick conversions to the other units.
Formula
All weights are converted through the kilogram: result = value × (kg per “from” unit) ÷ (kg per “to” unit). The exact international definition is 1 pound = 0.45359237 kg, so 1 kg = 2.2046226 lb. One ounce is 1/16 of a pound (28.349523 g) and one stone is 14 pounds (6.35029318 kg).
Worked examples
Body weight, kg to lb
A body weight of 70 kg is 154.32 lb.
Stone to kilograms
A UK weight of 11 stone is 69.853 kg (154 lb).
A recipe quantity
8 ounces of flour is 226.8 grams.
Common weight conversions
| Conversion | Result |
|---|---|
| 1 kg | 2.20462 lb |
| 1 lb | 0.453592 kg |
| 1 oz | 28.3495 g |
| 1 st | 14 lb |
| 100 kg | 220.462 lb |
| 150 lb | 68.0389 kg |
| 1 t | 1,000 kg |
Mass vs weight
Mass is the amount of matter in an object and stays the same everywhere. Weight is the force gravity exerts on it, which would be about one-sixth as large on the Moon. A kilogram or pound on a bathroom scale is really a mass reading, and that is how this converter treats it. See also the unit converter hub.
Practice problems
Try these yourself first, then check your answer. The answers come from the calculator above.
- Convert 12 stone to kilograms.
Show answer
12 st in kg: 76.20351816
- A 23 kg airline bag limit is how many pounds?
Show answer
23 kg in lb: 50.7063203
Common mistakes to avoid
- Mixing up the US short ton (2,000 lb), the UK long ton (2,240 lb) and the metric tonne (1,000 kg). This converter uses the metric tonne.
- Confusing ounces of weight with fluid ounces of volume — they are different quantities.
- Rounding 2.2 lb per kg too early on large values; the factor is closer to 2.2046.
Frequently asked questions
How many pounds are in a kilogram?
One kilogram is about 2.20462 pounds. Exactly, 1 lb = 0.45359237 kg.
How many ounces are in a pound?
There are 16 ounces in a pound (avoirdupois), the system used for everyday goods.
What is a stone in kilograms?
One stone is 14 pounds, or 6.35029318 kilograms.
Is a tonne the same as a ton?
No. A metric tonne is 1,000 kg, a US short ton is 2,000 lb (907.185 kg) and a UK long ton is 2,240 lb (1,016.05 kg).
Why do airlines use kilograms?
Most of the world uses the metric system; airlines apply kilograms for baggage allowances globally, with pounds shown in some US markets.
Sources and further reading
Reviewed September 26, 2026 by the SolveCalcPro editorial team. Found a mistake? Tell us; see our editorial policy.