This free converter turns pounds (lb) into kilograms (kg) and back, useful for anyone reconciling US or UK weights with the metric system — fitness logs, shipping labels, recipes, baggage allowances and medical records. The pound here is the international avoirdupois pound used in everyday weighing.
How it works
The conversion uses the exact factor defined by international agreement since 1959:
kilograms = pounds × 0.45359237
The reverse direction divides by the same factor (pounds = kilograms ÷ 0.45359237). Because the pound is defined in terms of the kilogram, this is an exact relationship, not a rounded approximation. The tool computes the result as you type in either field, so it works in both directions at once.
Example
To convert 165 lb to kilograms:
165 × 0.45359237 = 74.84 kg
Common values for quick reference:
| Pounds (lb) | Kilograms (kg) |
|---|---|
| 1 lb | 0.4536 kg |
| 5 lb | 2.268 kg |
| 10 lb | 4.5359 kg |
| 100 lb | 45.3592 kg |
| 165 lb | 74.8424 kg |
All calculations run entirely in your browser with no data sent to any server.