Last updated: September 2026
Weight conversion
Pounds to Kilograms (lb to kg)
Useful for medical records, travel baggage, fitness tracking, and international shipping labels.
1 lb
0.45359237 kg
kg = lb ÷ 2.20462262185
The formula
How to convert pounds to kilograms
Apply kg = lb ÷ 2.20462262185. For example, 1 lb equals 0.45359237 kg.
Precision
Accurate constants, readable results
OmniUnit calculates with the full stored conversion factor, then displays up to 12 significant digits.
Common pounds conversions
| Pounds | Kilograms |
|---|---|
| 1 lb | 0.45359237 kg |
| 5 lb | 2.26796185 kg |
| 10 lb | 4.5359237 kg |
| 50 lb | 22.6796185 kg |
| 100 lb | 45.359237 kg |
| 200 lb | 90.718474 kg |
Related weight conversions
Frequently asked questions
How many kilograms are in 1 pound?
One pound equals exactly 0.45359237 kilograms, by international definition. The pound is legally defined from the kilogram, so this factor is exact — not a measurement.
How many pounds are in 1 kilogram?
One kilogram equals 2.20462262185 pounds. To convert kilograms back to pounds, use the kilograms-to-pounds page, which shows the exact formula and a quick calculator.
How do I convert pounds to kilograms without a calculator?
Multiply the pounds by 0.454 for a quick estimate — for example, 10 pounds is about 4.54 kilograms. For precise results, use the calculator above.
Is the pound-to-kilogram conversion exact?
Yes. The pound is defined as exactly 0.45359237 kilograms, so this conversion is a fixed definition, not a measurement. OmniUnit calculates with the full stored factor for maximum precision.