Kilograms to Pounds
Convert kilograms (kg) to pounds (lb). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.
The Formula
``
pounds = kilograms × 2.20462262185
kilograms = pounds × 0.45359237
`
One kilogram is 2.2046 pounds, and one pound is 0.453592 kilograms.
Conversion Table
| Kilograms | Pounds |
|---|---|
| 1 kg | 2.2046 lb |
| 2 kg | 4.4092 lb |
| 5 kg | 11.0231 lb |
| 10 kg | 22.0462 lb |
| 25 kg | 55.1156 lb |
| 50 kg | 110.2311 lb |
| 100 kg | 220.4623 lb |
| 500 kg | 1,102.31 lb |
| 1,000 kg | 2,204.62 lb |
The Other Direction
| Pounds | Kilograms |
|---|---|
| 1 lb | 0.453592 kg |
| 2 lb | 0.907185 kg |
| 5 lb | 2.268 kg |
| 10 lb | 4.5359 kg |
| 25 lb | 11.3398 kg |
| 50 lb | 22.6796 kg |
| 100 lb | 45.3592 kg |
| 500 lb | 226.7962 kg |
| 1,000 lb | 453.5924 kg |
What Each Unit Is
Kilograms (kg) — defined since 2019 by fixing the Planck constant — the SI base unit of mass. Originally the mass of a litre of water, then a platinum-iridium cylinder near Paris until 2019.
Pounds (lb) — exactly 0.45359237 kilograms, by the 1959 international agreement. The Roman libra — which is why its symbol is lb — refined through the English avoirdupois system.
A Sense of Scale
A litre of water is 1 kg- A laptop is 1.5–2 kg
- Checked baggage allowance is often 23 kg
- A bag of sugar is 2 lb
- A newborn is 6–9 lb
- US body weight is given in pounds
Doing It in Your Head
Multiply by 11, then divide by 5. That is off by 0.21% — close enough to judge a
distance, a weight or a price, and not close enough to sign off on a drawing.
Exact Mental shortcut 22.0462 lb 22 lb 220.4623 lb 220 lb
Precision
The factor 2.20462262185 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.
In Code
`javascript
const kilogramToPound = (value) => value * 2.20462262185;
``
Where This Conversion Comes Up
- Cooking
- Shipping
- Fitness
- Medicine
- Manufacturing
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 kg with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 kg becomes | Error |
|---|---|---|---|
| 0 | 2 | 274 | 9.2815% |
| 1 | 2.2 | 301.4 | 0.2097% |
| 2 | 2.2 | 301.4 | 0.2097% |
| 3 | 2.205 | 302.085 | 0.0171% |
| 4 | 2.2046 | 302.03 | 0.0010% |
The right number of significant figures is set by your input, not by the converter. If you measured kilograms to three significant figures, the answer in pounds is only good to three — writing more digits claims precision the measurement never had.