Lbs to KG formula
1 pound = 0.45359237 kilograms, and 1 kilogram = 2.204622622 pounds. Exactly 0.45359237 kg (international pound, 1959).
Lbs to KG chart
| Pounds (lb) | Kilograms (kg) |
|---|---|
| 1 | 0.4536 |
| 2 | 0.9072 |
| 5 | 2.268 |
| 10 | 4.5359 |
| 15 | 6.8039 |
| 20 | 9.0718 |
| 25 | 11.3398 |
| 35 | 15.8757 |
| 45 | 20.4117 |
| 50 | 22.6796 |
| 60 | 27.2155 |
| 75 | 34.0194 |
| 100 | 45.3592 |
| 110 | 49.8952 |
| 120 | 54.4311 |
| 130 | 58.967 |
| 140 | 63.5029 |
| 150 | 68.0389 |
| 160 | 72.5748 |
| 170 | 77.1107 |
| 180 | 81.6466 |
| 190 | 86.1826 |
| 200 | 90.7185 |
| 220 | 99.7903 |
| 250 | 113.3981 |
Values are rounded to 4 decimal places. The converter above shows more precision.
Worked examples
A 45 lb barbell plate
45 lb × 0.45359237 = 20.4117 kg
45 pounds = 20.4117 kilograms. That is about 20.4 kg, slightly heavier than the 20 kg plate used in metric gyms. Mixing the two on one bar makes your logged weight wrong.
A person who weighs 180 lb
180 lb × 0.45359237 = 81.6466 kg
180 pounds = 81.6466 kilograms. Roughly 81.6 kg. A doctor or app working in metric units would record this as about 81.6 or 82 kg.
Converting pounds to kilograms in real life
Pounds show up whenever you deal with American sources: US recipes and food labels, product weights on US shopping sites, gym plates and dumbbells, and weight-loss plans written for an American audience. Medical dosing in most countries is worked out per kilogram of body weight, so a weight in pounds has to be converted first.
The pound is defined from the kilogram, not the other way round. Since 1959 one international pound has been exactly 0.45359237 kg, so this conversion has no hidden rounding.
The shortcut “halve it, then subtract 10% of the half” is very close: 200 lb becomes 100 − 10 = 90 kg, against an exact 90.72 kg. To check your result against healthy ranges, try the BMI calculator.