Pounds to Kilograms
1 lb = 0.45359237 kg exactly. Enter pounds, or pounds and ounces, and see the weight in kilograms or in kilograms and grams.
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Key Formula
1 lb ≈ 0.4536 kg
1 kg ≈ 2.2046 lb
Pounds → Kilograms
| lb | kg |
|---|---|
| 1 lb | 0.45 kg |
| 2 lb | 0.91 kg |
| 3 lb | 1.36 kg |
| 4 lb | 1.81 kg |
| 5 lb | 2.27 kg |
| 10 lb | 4.54 kg |
| 15 lb | 6.80 kg |
| 20 lb | 9.07 kg |
| 25 lb | 11.34 kg |
| 30 lb | 13.61 kg |
| lb | kg |
|---|---|
| 40 lb | 18.14 kg |
| 50 lb | 22.68 kg |
| 60 lb | 27.22 kg |
| 70 lb | 31.75 kg |
| 80 lb | 36.29 kg |
| 100 lb | 45.36 kg |
| 120 lb | 54.43 kg |
| 150 lb | 68.04 kg |
| 200 lb | 90.72 kg |
| 250 lb | 113.40 kg |
Have a weight in kilograms? Convert kg to pounds
How to convert pounds to kg
kg = lb × 0.45359237
Ounces are sixteenths of a pound: add them as oz ÷ 16 before multiplying.
150 pounds
- 150 lb × (0.45359237 kg / 1 lb)
- = 68.039 kg
8 lb 4 oz
- 4 oz ÷ 16 = 0.25 lb, so 8.25 lb
- 8.25 × 0.45359237 = 3.742 kg
- that is 3 kg 742 g
What is a pound?
The pound used for everyday weights in the U.S. is the avoirdupois pound, defined as exactly 0.453 592 37 kilograms. That value took effect in the United States on 1 July 1959 and was shared with the national standards laboratories of Australia, Canada, New Zealand, South Africa and the United Kingdom.
A pound has 16 ounces, so one ounce is 28.349 523 125 grams — the same figure NIST lists for ounce (avoirdupois) → kilogram, 2.834 952 × 10⁻².
Source: US Metric Association — Refinement of Values for the Yard and the Pound (retrieved 2026-09-29) / NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity or field of science (retrieved 2026-09-29)
References
Where the exact pound-to-kilogram factor comes from.
FAQ
150 × 0.45359237 = 68.04 kg.
200 × 0.45359237 = 90.72 kg.
0.45359237 kg — an exact value, not a rounded one.
A stone is 14 lb, so 11 st = 154 lb = 69.85 kg.