Pounds to KG Converter
Convert pounds to kilograms instantly, with a reference table covering body weight, luggage limits and gym plates.
LBS to KG Converter
1 lb = 0.4536 kg
Multiply pounds by 0.45359237 to get kilograms.
The link carries the values you entered, so whoever opens it sees the same result. Nothing is stored on our side — the numbers travel in the link itself.
Pounds to kilograms reference table
The conversions people look up most often, rounded to 4 decimal places.
| Pound (lb) | Kilogram (kg) |
|---|---|
| 1 lb | 0.4536 kg |
| 5 lb | 2.268 kg |
| 10 lb | 4.5359 kg |
| 25 lb | 11.3398 kg |
| 45 lb | 20.4117 kg |
| 50 lb | 22.6796 kg |
| 100 lb | 45.3592 kg |
| 120 lb | 54.4311 kg |
| 135 lb | 61.235 kg |
| 150 lb | 68.0389 kg |
| 180 lb | 81.6466 kg |
| 200 lb | 90.7185 kg |
| 225 lb | 102.0583 kg |
The pounds people look up most
- 45 lb = 20.4117 kg
- An American Olympic plate. It is 20.41 kg, not the 20 kg plate used everywhere else - which is why a 225 lb bench is 2 kg heavier than a 100 kg one.
- 50 lb = 22.6796 kg
- The US domestic airline baggage limit. It clears the 23 kg international limit with 300 g to spare.
- 135 lb = 61.235 kg
- A loaded Olympic bar with two 45 lb plates - the first milestone in most American gyms.
- 150 lb = 68.0389 kg
- A common body weight in pounds. Halve it and take off 10% for a quick mental conversion.
- 200 lb = 90.7185 kg
- A round imperial bodyweight target that lands nowhere near a round metric one.
How the lbs to kg calculation works
A pound is exactly 0.45359237 kilograms:
kilograms = pounds × 0.45359237
That figure is a definition, agreed internationally in 1959. Before it, the US and UK pounds differed slightly — by about one part in ten million, enough to matter in trade but not on a bathroom scale.
Gym plates are the case where the difference is most visible. American plates are 45 lb, which is 20.41 kg — not the 20 kg plate used everywhere else. A loaded Olympic bar makes the gap compound:
- Bar alone: 45 lb = 20.41 kg vs a 20 kg metric bar
- Bar + two 45s: 135 lb = 61.23 kg vs 60 kg metric
- Bar + four 45s: 225 lb = 102.06 kg vs 100 kg metric
A "225 lb bench" and a "100 kg bench" are not the same lift; the imperial one is 2 kg heavier.
Airline baggage is the other everyday case. A 50 lb US domestic limit is 22.68 kg, while most international carriers set 23 kg — so a bag packed to the US limit clears the international one with 300 g to spare. A 40 lb limit is 18.14 kg.
The mental shortcut is halve it, then take off 10%: 150 lb → 75 → 67.5, against a true 68.04 kg. Accurate to within a percent across normal body weights.
To convert back, multiply kilograms by 2.20462.
Frequently asked questions
Why do boxing weight classes convert to such untidy kilogram figures?
Because each sport fixed its limits in one system and left the other to fall where it may. Professional boxing sets its divisions in pounds - welterweight at 147 lb is 66.68 kg - while Olympic weightlifting and judo set theirs in kilograms and leave the pound figures ragged. A fighter makes weight in whichever unit the commission uses, because rounding a converted limit the wrong way fails the scale.
Do I need kilograms to work out BMI?
The formula is defined in metric: kilograms divided by height in metres squared. The imperial version multiplies pounds divided by inches squared by 703, and that constant exists purely to absorb the unit conversion. If your weight is in pounds, converting to kilograms first and using the metric formula is less error-prone than carrying an unexplained 703 through the sum.
What does a weight quoted in tons mean?
One of three things, up to 12% apart. A US short ton is 2,000 lb, or 907.18 kg; a British long ton is 2,240 lb, or 1,016.05 kg; and a metric tonne is 1,000 kg, or 2,204.62 lb. Freight rates, emissions figures and scrap prices are all quoted per ton without always saying which. The spelling is a partial clue, since tonne almost always means the metric one.
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