Lb to kg conversion formula
The pound (lb) is a unit of mass defined as exactly 0.45359237 kilograms since 1959. It is the everyday weight unit in the United States.
The kilogram (kg) is the SI base unit of mass, defined since 2019 by the Planck constant. Used worldwide for body weight, food and trade.
Lb to kg conversion table
| lb | kg |
|---|---|
| 1 lb | 0.453592 kg |
| 2 lb | 0.907184 kg |
| 3 lb | 1.3608 kg |
| 5 lb | 2.268 kg |
| 10 lb | 4.5359 kg |
| 20 lb | 9.0718 kg |
| 25 lb | 11.3398 kg |
| 50 lb | 22.6796 kg |
| 100 lb | 45.3592 kg |
| 250 lb | 113.398 kg |
| 500 lb | 226.796 kg |
| 1000 lb | 453.592 kg |
How to convert lb to kg
- Write down the value in lb you want to convert.
- Multiply it by 0.453592 — or use the converter above, which does it instantly.
- Read your result in kg. Done.
Real-world examples
- An average adult man in the US weighs about 199 lb — 90.3 kg.
- A standard bowling ball tops out at 16 lb — 7.26 kg, the legal maximum.
- Checked-luggage limit on most airlines: 50 lb — 22.7 kg before the overweight fee kicks in.
- The heaviest bench press ever is 782.6 lb — 355 kg.
Common mistakes
The #1 error is halving instead of exact conversion: “100 lb is about 45 kg” is fine for luggage, but the precise factor is 0.4536 — the gap grows with the weight (200 lb is 90.7 kg, not 90). Second trap: the pound in the US is defined through the kilogram since 1959 — a “pound” measured in London and a pound in Chicago are the same unit. But never confuse it with the stone (14 lb), still used for body weight in the UK: a British friend “11 stone” weighs 154 lb, not 11.
Quick mental conversion
The reliable shortcut: divide by 2, then subtract 10% of the result. 150 lb → 75 → minus 7.5 = 67.5 kg (exact: 68.0). For the reverse, double and add 10%: 80 kg → 160 + 16 = 176 lb (exact: 176.4 — the trick is nearly perfect both ways).
Frequently asked questions
How many kg is 1 lb?
Using the official conversion factor, 1 pound = 0.453592 kilogram. The converter above handles any value instantly.
What is the formula to convert pound to kilogram?
1 pound = 0.453592 kilogram. Multiply any value in lb by this factor to get kg.
Is this lb to kg converter free?
Yes — 100% free, unlimited, with no sign-up. CalculUnits is funded by non-intrusive ads, never by paywalls.