Pound to Kilogram (lb to kg)
Result
0.45359237 Kilogram
Formula
kg = lb × 0.45359237
1 lb = 0.45359237 kg, and 1 kg = 2.204622622 lb.
The kilogram is the SI base unit of mass, defined through the Planck constant since 2019. The international avoirdupois pound is exactly 0.45359237 kg; the ounce is 1/16 lb and the stone 14 lb.
Worked examples
- 1 lb × 0.45359237 = 0.45359237 kg
- 50 lb × 0.45359237 = 22.679619 kg
- 150 lb × 0.45359237 = 68.038855 kg
- 200 lb × 0.45359237 = 90.718474 kg
Things to know about lb to kg
- Multiply by 0.45359237 (exact). A rough mental estimate is to halve and subtract 10%: 200 lb ≈ 90 kg (exactly 90.72).
- This is the avoirdupois pound. The troy pound (373.24 g) is only used for precious metals.
Pound to Kilogram table
| Pound (lb) | Kilogram (kg) |
|---|---|
| 1 | 0.45359237 |
| 2 | 0.90718474 |
| 5 | 2.2679619 |
| 10 | 4.5359237 |
| 20 | 9.0718474 |
| 50 | 22.679619 |
| 100 | 45.359237 |
| 150 | 68.038855 |
| 200 | 90.718474 |
| 1,000 | 453.59237 |
The units
- Pound (lb)
- The international avoirdupois pound, exactly 0.45359237 kg.
- Kilogram (kg)
- The SI base unit of mass, defined through the Planck constant since May 2019.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy