About This Pounds to Kilograms Converter
The pound (lb) is the US customary and imperial unit of mass, used for body weight, grocery quantities, and shipping in the United States and UK. The kilogram (kg) is the SI base unit of mass, used by virtually every other country for the same purposes. One pound equals exactly 0.45359237 kilograms — a definition adopted internationally in 1959.
This converter supports six mass units: pounds, kilograms, grams, ounces, stone, and metric tons. Athletes tracking body weight for international competitions, travelers checking airline baggage limits stated in kg, and nutritionists converting US recipe quantities to metric measures all rely on this conversion throughout their work.
How to Use This Converter
- Enter your weight value in the Value field.
- Confirm Pound is selected in the From dropdown.
- Select Kilogram in the To dropdown (or any other target unit).
- The converted result and formula appear instantly.
- Use Swap to flip between lbs and kg in one click.
Units Covered
| Unit | Symbol | Common Use |
|---|---|---|
| Pound | lb | Body weight and grocery quantities in the US; shipping weights |
| Kilogram | kg | Body weight, food, and mass in metric countries; SI standard |
| Gram | g | Food nutrition labels, postal weights, small ingredient quantities |
| Ounce | oz | US cooking measurements, postal weights, precious metals |
| Stone | st | UK body weight (1 stone = 14 pounds = 6.35 kg) |
| Metric Ton | t | Freight, bulk commodities, industrial quantities |
Pounds to Kilograms Conversion Table
| Pounds [lb] | Kilograms [kg] |
|---|---|
| 1 lb | 0.4536 kg |
| 5 lb | 2.268 kg |
| 10 lb | 4.536 kg |
| 25 lb | 11.34 kg |
| 50 lb | 22.68 kg |
| 100 lb | 45.36 kg |
| 120 lb | 54.43 kg |
| 150 lb | 68.04 kg |
| 180 lb | 81.65 kg |
| 200 lb | 90.72 kg |
| 250 lb | 113.4 kg |
| 500 lb | 226.8 kg |
How to Convert Pounds to Kilograms
To convert pounds to kilograms, multiply by 0.453592:
Example: Convert 165 lb to kilograms:
To convert kilograms back to pounds, divide by 0.453592 (or multiply by 2.20462):
Example: Convert 70 kg to pounds:
When You Need to Convert Pounds to Kilograms
International travel is the most common trigger. Airlines flying out of US airports allow baggage weight in pounds on domestic routes but enforce kilograms on international ones — a 50 lb bag is 22.68 kg, just under the standard 23 kg economy allowance. Getting this wrong at the check-in counter costs $75–$200 in overweight fees.
Fitness and sports medicine cross the unit boundary constantly. A US athlete who weighs 185 lb needs to enter 83.9 kg for European competition registration, medication dosing by body weight, or VO2 max calculations that use kg. Weight class sports — boxing, wrestling, weightlifting, judo — define classes in kilograms at international events even when athletes train in environments that count pounds.
Recipe and nutrition conversion is another everyday need. US recipes list ingredients in cups, ounces, and pounds; international recipes and professional food science use grams and kilograms. Scaling a restaurant recipe from 10 lb of flour to kilograms (4.536 kg) for a metric-calibrated commercial scale is a straightforward conversion that prevents wasteful mis-measurement.