UnitSnapPounds to Kilograms
1 lb = 0.4535924 kg
Pounds to kilograms is needed by Americans filling out international forms, travelers flying with metric baggage limits, and patients whose medication doses are calculated per kilogram. The pound is defined as exactly 0.45359237 kg, so a weight in pounds can be converted precisely for medical or official use.
When you need to convert pounds to kilograms
- Entering a body weight on a visa, medical, or airline form that requires kilograms
- Checking weight-based medication or anesthesia dosing that uses kilograms
- Converting a lifting personal record for a competition scored in kilograms
- Shipping a package internationally where carriers quote rates per kilogram
How to convert pounds to kilograms
kg = lb × 0.4535924
Example: 5 lb = 2.267962 kg
Common body weights
| Pounds (lb) | Kilograms (kg) |
|---|---|
| 100 lb | 45.35924 kg |
| 120 lb | 54.43108 kg |
| 130 lb | 58.96701 kg |
| 150 lb | 68.03886 kg |
| 160 lb | 72.57478 kg |
| 180 lb | 81.64663 kg |
| 200 lb | 90.71847 kg |
| 220 lb | 99.79032 kg |
| 250 lb | 113.3981 kg |
Tips for converting pounds to kilograms
- Divide pounds by 2.2 for an estimate within about 0.2% of the exact figure.
- Mental shortcut: halve the pounds, then subtract 10% of that half. The result is within about 1%.
- For medication dosing, always use the exact conversion and do not round until the final step.
Pounds to Kilograms conversion table
| Pounds (lb) | Kilograms (kg) |
|---|---|
| 1 lb | 0.4535924 kg |
| 2 lb | 0.9071847 kg |
| 3 lb | 1.360777 kg |
| 4 lb | 1.814369 kg |
| 5 lb | 2.267962 kg |
| 6 lb | 2.721554 kg |
| 7 lb | 3.175147 kg |
| 8 lb | 3.628739 kg |
| 9 lb | 4.082331 kg |
| 10 lb | 4.535924 kg |
| 15 lb | 6.803886 kg |
| 20 lb | 9.071847 kg |
| 25 lb | 11.33981 kg |
| 30 lb | 13.60777 kg |
| 40 lb | 18.14369 kg |
| 50 lb | 22.67962 kg |
| 75 lb | 34.01943 kg |
| 100 lb | 45.35924 kg |
| 250 lb | 113.3981 kg |
| 500 lb | 226.7962 kg |
| 1,000 lb | 453.5924 kg |
About the units
Pounds: The pound (avoirdupois) is a US customary and imperial unit of mass defined as exactly 0.45359237 kilograms.
Kilograms: The kilogram is the SI base unit of mass, defined through the Planck constant. It is the everyday unit for body weight and groceries in most countries.
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Frequently asked questions
How many kilograms are in 1 pound?
1 pound equals 0.4535924 kilograms.
How many pounds are in 1 kilogram?
1 kilogram equals 2.204623 pounds.
How do I convert pounds to kilograms?
Use the formula kg = lb × 0.4535924.
What is 10 pounds in kilograms?
10 pounds equals 4.535924 kilograms.
Related conversions
Factors: NIST SP 811 · SI Brochure · NIST Handbook 44 — Updated