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Pounds to Kilograms (lb to kg)
Convert pounds to kilograms: 1 lb = 0.453592 kg. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 lb = 0.453592 kg
kilograms = pounds × 0.45359237 — reverse: pounds = kilograms × 2.204622622
The factor is derived from the SI definitions of both units (base unit: kg) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.
Worked examples
- 5 lb = 2.26796 kg
- 12.5 lb = 5.6699 kg
- 100 lb = 45.3592 kg
Pounds to kilograms conversion table
| Pounds (lb) | Kilograms (kg) |
|---|---|
| 1 | 0.453592 |
| 2 | 0.907185 |
| 3 | 1.36078 |
| 4 | 1.81437 |
| 5 | 2.26796 |
| 6 | 2.72155 |
| 7 | 3.17515 |
| 8 | 3.62874 |
| 9 | 4.08233 |
| 10 | 4.53592 |
| 15 | 6.80389 |
| 20 | 9.07185 |
| 25 | 11.3398 |
| 30 | 13.6078 |
| 40 | 18.1437 |
| 50 | 22.6796 |
| 75 | 34.0194 |
| 100 | 45.3592 |
| 200 | 90.7185 |
| 250 | 113.398 |
| 500 | 226.796 |
| 1000 | 453.592 |
FAQ
How many kilograms are in one pound?
1 lb = 0.453592 kg. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.
What is the formula to convert pounds to kilograms?
Multiply the value in pounds by 0.45359237: kilograms = pounds × 0.45359237. For example, 5 lb = 2.26796 kg.
How do I convert kilograms back to pounds?
Multiply by the inverse factor 2.204622622 (pounds = kilograms × 2.204622622), or use the kilograms-to-pounds page.
Related conversions
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=lb&to_unit=kg - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"lb","to_unit":"kg"} - Markdown: https://tttkmbb.com/conversion/lbs-to-kg.md · JSON: https://tttkmbb.com/conversion/lbs-to-kg.json (add
?value=for a result) · Units: /api/v1/units?quantity=mass - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.