Pounds to Kilograms
Result:
Enter a weight to convert.
Convert pounds to kilograms. From is set to pounds and To is set to kilograms. The result updates as you type. One avoirdupois pound is exactly 0.45359237 kilograms. Other units are on the weight converter. The other direction is kilograms to pounds.
Pounds to kilograms formula
NIST Handbook 44 (2024), Appendix B states that 1 avoirdupois pound = 0.45359237 kilogram exactly.
Formula: kilograms = pounds × 0.45359237.
The converter multiplies by that exact pound, then rounds the displayed result to five decimal places. One pound shows 0.45359 kg, because the next digit is 2.
Example: 150 lb × 0.45359237 = 68.03886 kg.
Pounds to kilograms reference table
Each value below is the converter result at five decimal places. Enter the same pounds in the form above and the result should match.
| Pounds | Kilograms |
|---|---|
| 1 | 0.45359 |
| 2 | 0.90718 |
| 5 | 2.26796 |
| 10 | 4.53592 |
| 20 | 9.07185 |
| 25 | 11.33981 |
| 50 | 22.67962 |
| 75 | 34.01943 |
| 100 | 45.35924 |
| 120 | 54.43108 |
| 150 | 68.03886 |
| 180 | 81.64663 |
| 200 | 90.71847 |
| 250 | 113.39809 |
Pounds to kilograms examples
Body weight: A bathroom-scale reading of 150 lb is 150 × 0.45359237 = 68.03886 kg. To use that weight for adult BMI, the BMI calculator accepts either unit.
Luggage: If a checked-bag allowance is printed as 50 lb, that is 22.67962 kg. A bag that reads 23 kg at the counter is slightly over that figure.
Groceries: A 10 lb bag of potatoes is 4.53592 kg, and a 5 lb bag of flour is 2.26796 kg.
Quick mental math (approximation)
To estimate kilograms, halve the pounds, then subtract 10 percent of that half. That is the same as multiplying by 0.45. Example: 150 lb halved is 75, minus 7.5 is about 67.5 kg. The exact result is 68.03886 kg.
This shortcut is an approximation. It runs about 0.8 percent low. Use the converter or the exact formula when the number goes on a label, form, or record.
Pounds to kilograms FAQ
How many kilograms are in a pound?
Exactly 0.45359237 kilograms. The converter rounds that to five decimal places and shows 0.45359 kg.
Can I divide by 2.2 instead?
For a rough estimate, yes. Dividing by 2.2 runs about 0.2 percent high. Example: 150 ÷ 2.2 is about 68.18 kg, while the exact result is 68.03886 kg.
Why does 1 lb show 0.45359 kg and not 0.45359237?
The converter displays five decimal places. The next digit after 0.45359 is 2, so it rounds down. The calculation itself uses the full exact factor.