What this calculator does
Pounds to kilos is one of the most common weight conversions there is, since body weight, luggage limits and food packaging all switch between the two depending on the country and the context.
The conversion is exact: one pound equals precisely 0.45359237 kilograms. Enter a value in either unit, choose the direction, and the other unit comes out immediately, with the equivalent in stone included for body-weight conversions.
The formula
To convert pounds to kilos, multiply by 0.45359237. To convert kilos to pounds, divide by the same figure, or equivalently multiply by 2.2046226. The pound has been defined this way, tied exactly to the kilogram, since the 1959 international agreement on weights and measures.
| Term | Meaning |
|---|---|
| Pound (lb) | A US customary and imperial unit of mass, exactly 0.45359237 kilograms. |
| Kilogram (kg) | The SI base unit of mass. |
| Stone (st) | 14 pounds, roughly 6.35 kg, used mainly for body weight in the UK and Ireland. |
The inputs explained
| Field | What to enter |
|---|---|
| Value | The value to convert. |
| Convert | Choose whether to convert pounds to kilos, or kilos to pounds. |
When to use it
Converting body weight between systems
A weight quoted in pounds on a US scale, or in kilos on a metric one, converts directly, with the stone figure alongside for UK and Irish readers who think in stone and pounds.
Checking an airline baggage limit
Baggage weight limits are sometimes quoted in kilos and sometimes in pounds depending on the airline and the region, and travellers packing to a specific limit need the exact figure, not a rough estimate.
Converting a recipe or ingredient weight
A US recipe listing ingredients in pounds converts to kilograms for a kitchen scale calibrated in metric, keeping proportions accurate.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Pounds to kilos, at common body-weight values
A range of pound values, each converted to kilograms.
| Pounds | Kilograms | Stone (14 lb) |
|---|---|---|
| 10 | 4.536 | 0.71 st |
| 50 | 22.680 | 3.57 st |
| 100 | 45.359 | 7.14 st |
| 150 | 68.039 | 10.71 st |
| 200 | 90.718 | 14.29 st |
| 250 | 113.398 | 17.86 st |
Kilos to pounds, at common body-weight values
A range of kilogram values, each converted to pounds.
| Kilograms | Pounds | Stone (14 lb) |
|---|---|---|
| 5 | 11.023 | 0.79 st |
| 25 | 55.116 | 3.94 st |
| 50 | 110.231 | 7.87 st |
| 70 | 154.324 | 11.02 st |
| 90 | 198.416 | 14.17 st |
| 120 | 264.555 | 18.90 st |
Questions
How do I convert pounds to kilos?
Multiply the number of pounds by 0.45359237. For a quick estimate, multiplying by 0.45 gets close, but the exact factor matters for anything where precision counts, such as a strict luggage limit.
How do I convert kilos to pounds?
Divide the number of kilograms by 0.45359237, or multiply by 2.2046226. Both give the same result: roughly 2.2 pounds for every kilogram.
How many kilos is 150 pounds?
150 lb converts to about 68.04 kg, using the exact 0.45359237 kg-per-pound factor.
Why is the pound defined in terms of the kilogram?
Since the 1959 international agreement on weights and measures, the pound has been legally defined as exactly 0.45359237 kg, rather than the kilogram being defined from the pound. This removed the small historical differences that used to exist between the US and imperial pound.
For the full metric and imperial mass ladder, milligrams up to tonnes and both kinds of ton, see the weight & mass converter. For height and weight together, see the height & weight converter.