Pounds to Kilograms Converter
Convert pounds to kilograms and back. 1 pound = 0.45359237 kilograms exactly.
Tip: Results show up to 8 significant digits. The factors and their sources are listed on the "Where our numbers come from" page.
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Pounds and Kilograms
One pound is exactly 0.45359237 kilograms, and one kilogram is about 2.20462262185 pounds. The converter works both ways: use the two tabs at the top of the tool to choose the direction.
Quick conversion table
Pounds to Kilograms
| Pounds | Kilograms |
|---|---|
| 1 lb | 0.45359237 kg |
| 2 lb | 0.90718474 kg |
| 5 lb | 2.2679619 kg |
| 10 lb | 4.5359237 kg |
| 20 lb | 9.0718474 kg |
| 50 lb | 22.679619 kg |
| 100 lb | 45.359237 kg |
| 120 lb | 54.431084 kg |
| 150 lb | 68.038856 kg |
| 180 lb | 81.646627 kg |
| 200 lb | 90.718474 kg |
| 250 lb | 113.39809 kg |
Kilograms to Pounds
| Kilograms | Pounds |
|---|---|
| 1 kg | 2.2046226 lb |
| 2 kg | 4.4092452 lb |
| 5 kg | 11.023113 lb |
| 10 kg | 22.046226 lb |
| 20 kg | 44.092452 lb |
| 50 kg | 110.23113 lb |
| 60 kg | 132.27736 lb |
| 70 kg | 154.32358 lb |
| 80 kg | 176.36981 lb |
| 90 kg | 198.41604 lb |
| 100 kg | 220.46226 lb |
| 150 kg | 330.69339 lb |
Exact factor and source
| Conversion | Value | Basis |
|---|---|---|
| 1 pound in kilograms | 0.45359237 | exact. NIST SP 811 (2008), Appendix B.8: 1 lb (avoirdupois) = 0.45359237 kg, exact by the 1959 international yard and pound agreement |
| 1 kilogram in pounds | 2.20462262185 | rounded to 12 digits. SI Brochure, 9th edition (BIPM 2019): SI base unit of mass |
How to convert pounds to kilograms
- Step oneTake the number of pounds.
- Step twoMultiply it by 0.45359237.
- Step threeThe result is the number of kilograms.
- Step fourTo go back, divide by 0.45359237, or multiply by 2.20462262185.
Example: 150 lb x 0.45359237 = 68.0388555 kg.
All weight units compared
Each unit written in grams, the base unit of this tool. Exact values come straight from the definitions.
| Unit | Symbol | Value in grams |
|---|---|---|
| Grams | g | 1 gram |
| Kilograms | kg | 1,000 grams |
| Ounces | oz | 28.349523125 grams |
| Pounds | lb | 453.59237 grams |
What is a pound?
The pound (lb) is exactly 0.45359237 kilograms, or 16 ounces. It is used for body weight, produce and shipping in the US.
What is a kilogram?
The kilogram (kg) is the SI base unit of mass, equal to 1,000 grams or about 2.20462262185 pounds. It is used for body weight, groceries and parcels outside the US.
What this converter does not do
- Results are rounded for display to 8 significant digits; the stored factor is the exact one.
- It converts mass in avoirdupois units (the pound and ounce of everyday use), not troy ounces, which are used for precious metals.
- It does not convert between a weight and a volume, because that needs the density of the material.
Frequently asked questions
How many kilograms are in a pound?
1 pound is exactly 0.45359237 kilograms. That factor is exact by definition.
How many pounds are in a kilogram?
1 kilogram is about 2.20462262185 pounds.
How many kilograms is 150 pounds?
150 pounds is 68.038856 kilograms.
Where do the factors come from?
Pounds: NIST SP 811 (2008), Appendix B.8: 1 lb (avoirdupois) = 0.45359237 kg, exact by the 1959 international yard and pound agreement. Kilograms: SI Brochure, 9th edition (BIPM 2019): SI base unit of mass.
References
- Pounds: NIST SP 811 (2008), Appendix B.8: 1 lb (avoirdupois) = 0.45359237 kg, exact by the 1959 international yard and pound agreement
- Kilograms: SI Brochure, 9th edition (BIPM 2019): SI base unit of mass
- NIST Special Publication 811: Guide for the Use of the International System of Units (SI), 2008 edition.
- The International System of Units (SI Brochure), 9th edition, BIPM.