One pound is exactly 0.45359237 kilograms. Type a weight above and you get it in kilograms, grams, ounces, stones and tons at once; choose another unit in the list to convert the other way.
Pounds to kilograms
| Pounds | Kilograms |
|---|---|
| 1 | 0.454 |
| 2 | 0.907 |
| 5 | 2.268 |
| 10 | 4.536 |
| 25 | 11.340 |
| 50 | 22.680 |
| 100 | 45.359 |
| 150 | 68.039 |
| 200 | 90.718 |
| 250 | 113.398 |
Kilograms to pounds
| Kilograms | Pounds |
|---|---|
| 1 | 2.20 |
| 5 | 11.02 |
| 10 | 22.05 |
| 20 | 44.09 |
| 23 | 50.71 |
| 50 | 110.23 |
| 60 | 132.28 |
| 70 | 154.32 |
| 80 | 176.37 |
| 90 | 198.42 |
| 100 | 220.46 |
Stones for body weight
In the UK and Ireland, bathroom scales and doctors often use stone and pounds. One stone is 14 lb:
| Stone | Pounds | Kilograms |
|---|---|---|
| 8 st | 112 | 50.8 |
| 9 st | 126 | 57.2 |
| 10 st | 140 | 63.5 |
| 11 st | 154 | 69.9 |
| 12 st | 168 | 76.2 |
| 13 st | 182 | 82.6 |
| 14 st | 196 | 88.9 |
| 15 st | 210 | 95.3 |
| 16 st | 224 | 101.6 |
| 18 st | 252 | 114.3 |
| 20 st | 280 | 127.0 |
For a weight like 11 st 7 lb, add the pounds to the stone row: 154 + 7 = 161 lb, which is 73.0 kg. The BMI and calorie calculators accept stone directly.
Three different tons
| Ton | Pounds | Kilograms | Used in |
|---|---|---|---|
| Metric ton (tonne) | 2,204.6 | 1,000 | Almost everywhere |
| Short ton | 2,000 | 907.2 | United States |
| Long ton | 2,240 | 1,016.0 | United Kingdom (traditional), shipping |
When a document says “ton”, check which one it means: the difference between a short and a long ton is 12%.
Why the pound has eight decimals
Since 1959 the international pound has been defined as exactly 0.45359237 kg. The long string of decimals means the conversion is exact, not measured, so a pharmacist in Chicago and a baker in Melbourne get the same result for the same number of pounds.
Mental shortcuts
- Pounds to kilograms: halve it, then take away 10% of the half. 180 lb → 90 → 81 kg (exactly 81.6).
- Kilograms to pounds: double it, then add 10%. 65 kg → 130 → 143 lb (exactly 143.3).
Once opened, the converter keeps working with no signal, which is useful at an airport check-in desk.
Frequently asked questions
How many kilograms are in a pound?
0.45359237 exactly. To get kilograms, multiply pounds by 0.4536, or divide them by 2.2046.
How many pounds are in a kilogram?
2.20462. A quick estimate: double the kilograms and add 10%. 70 kg × 2 = 140, plus 14 = 154 lb (exactly 154.32).
How heavy is a stone?
14 pounds, or 6.35 kg. People in the UK and Ireland often give their weight in stone and pounds: 11 st 7 lb is 161 lb, or 73.0 kg.
Is a ton 1,000 kg?
Only the metric ton (tonne) is. A US short ton is 2,000 lb (907.2 kg) and a UK long ton is 2,240 lb (1,016 kg).
What is a 23 kg baggage limit in pounds?
50.7 lb. Airlines that work in pounds usually round it to 50 lb, which is 22.7 kg – so a bag that is fine in one system can be just over in the other.
Sources
- NIST Special Publication 811: Guide for the Use of the SI, Appendix B (conversion factors)
- UK Weights and Measures Act 1985, Schedule 1
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