Convert Pounds to Kilograms
1 pound (lb) equals 0.45359237 kilograms (kg).
1 lb = 0.45359237 kg
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk pound to kilogram converter to paste a column from Excel.
How to Convert Pound to Kilogram
- 1 lb = 0.45359237 kg
- 1 kg = 2.204622622 lb
- Example: convert 150 lb to kg: 150 lb = 150 × 0.45359237 kg = 68.0388555 kg
Reference conditions. lb: Avoirdupois system: 1 lb = 16 oz = 7000 grains = 0.45359237 kg exactly (1959 agreement).
Formula
kg = lb × 0.45359237
or kg = lb ÷ 2.204622621849
Derivation from SI units:
- 1 lb = 0.45359237 kg (exact, 1959 international agreement)
- SI base unit, fixed by the Planck constant h = 6.626 070 15 × 10⁻³⁴ J·s
Both units are defined exactly, so the factor is exact. Pound definition: pound; Kilogram definition: kilogram.
Worked examples
- A body weight of 150 lb is 68.0388555 kg.
150 lb × 0.45359237 = 68.0388555 kg - A 50 lb bag of feed is 22.6796185 kg.
50 lb × 0.45359237 = 22.6796185 kg
Pound to Kilogram conversion table
| Pounds (lb) | Kilograms (kg) |
|---|---|
| 0.25 lb | 0.1133980925 kg |
| 0.5 lb | 0.226796185 kg |
| 1 lb | 0.45359237 kg |
| 2 lb | 0.90718474 kg |
| 3 lb | 1.36077711 kg |
| 5 lb | 2.26796185 kg |
| 10 lb | 4.5359237 kg |
| 15 lb | 6.80388555 kg |
| 20 lb | 9.0718474 kg |
| 25 lb | 11.33980925 kg |
| 30 lb | 13.6077711 kg |
| 40 lb | 18.1436948 kg |
| 50 lb | 22.6796185 kg |
| 100 lb | 45.359237 kg |
| 120 lb | 54.4310844 kg |
| 130 lb | 58.9670081 kg |
| 140 lb | 63.5029318 kg |
| 150 lb | 68.0388555 kg |
| 160 lb | 72.5747792 kg |
| 170 lb | 77.1107029 kg |
| 180 lb | 81.6466266 kg |
| 200 lb | 90.718474 kg |
| 220 lb | 99.7903214 kg |
| 250 lb | 113.3980925 kg |
| 300 lb | 136.077711 kg |
Where it's used
US weights in pounds are converted to kilograms for medical dosing, shipping documents and international sport. Multiply by exactly 0.45359237.
Pound to other weight and mass units
| Conversion | 1 lb equals |
|---|---|
| pound to kilogram | 0.45359237 kg |
| pound to gram | 453.59237 g |
| pound to milligram | 453592.37 mg |
| pound to microgram | 453592370 µg |
| pound to metric ton | 0.00045359237 t |
| pound to ounce | 16 oz |
| pound to stone | 0.07142857143 st |
| pound to short ton | 0.0005 ton (US) |
| pound to long ton | 0.0004464285714 ton (UK) |
| pound to grain | 7000 gr |
| pound to troy ounce | 14.58333333 oz t |
| pound to carat | 2267.96185 ct |
Frequently asked questions
Is a pound 0.45 kg?
Close: 1 lb = 0.45359237 kg exactly. Dividing by 2.2 instead gives an error of about 0.2 %.
How many kilograms are in 1 pound?
1 lb = 0.45359237 kg.
How do I convert pounds to kilograms?
Multiply the value in lb by 0.45359237, or divide it by 2.204622622. For example, 150 lb × 0.45359237 = 68.0388555 kg.
Is the lb to kg conversion exact?
Yes. Both units are defined exactly, and 1 lb is exactly 0.45359237 kg.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "pound (avoirdupois) (lb)".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Section 2.3.1, base unit definitions.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Pounds to Kilograms. Retrieved October 17, 2026, from https://scientificconverters.com/mass/pounds-to-kilograms/
IEEE
Scientific Converters, "Convert Pounds to Kilograms," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/mass/pounds-to-kilograms/