Pound to Kilogram Converter
Convert pound (lb) to kilogram (kg) instantly, with the exact conversion factor and a table of common values.
How it works
Pound and kilogram are both units of weight, so converting between them is a single multiplication by a fixed factor — there is no rounding rule or regional variation to worry about.
The factor used here is exact: 1 lb is defined as 0.45359237 kg. Results are shown to enough decimal places to stay useful for small values without turning large ones into noise.
The formula
Pound → Kilogram
kg = lb × 0.45359237
Kilogram → Pound
lb = kg ÷ 0.45359237
Worked examples
| Scenario | Working | Result |
|---|---|---|
| 1 lb | 1 × 0.45359237 | 0.45359237 kg |
| 5 lb | 5 × 0.45359237 | 2.268 kg |
| 10 lb | 10 × 0.45359237 | 4.5359 kg |
| 20 lb | 20 × 0.45359237 | 9.0718 kg |
When you'd use it
- Reading a recipe, spec sheet or label written in the other system
- Filling in a form that expects a specific unit
- Checking luggage, shipping or equipment limits
- Coursework and lab reports that require SI units
Common questions
How many kilogram are in a pound?
One pound equals 0.45359237 kilogram. Multiply by that number to convert, or divide by it to go the other way.
Is the conversion exact?
The factor is exact by definition — these units are defined in terms of each other. Only the display is rounded, and you can copy the full-precision result.
Why does my answer differ slightly from another converter?
Almost always rounding. Some converters round the factor itself before multiplying, which compounds the error on large values. This one multiplies first and rounds only for display.