# Stone and pounds to kg converter

Converts stone and pounds to kilograms: kg = (st × 14 + lb) × 0.45359237.

- Page: https://www.acalculator.org/convert/stone-and-lbs-to-kg
- JSON spec: https://www.acalculator.org/convert/stone-and-lbs-to-kg.json
- Version: 2532c500cfd5

## Default answer

Example with the default inputs (Stone (st) 11, Pounds (lb) 4): 11 st 4 lb = 71.667594 kg.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Stone (st) | The whole stone. |
| lb | Pounds (lb) | The pounds on top of the stone. |
| result | Kilograms (kg) | The weight in kilograms. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Stone (st) | The whole stone. |
| lb | Pounds (lb) | The pounds on top of the stone. |
| result | Kilograms (kg) | The weight in kilograms. |

## Method

kg = (st × 14 + lb) × 0.45359237

## Assumptions

- 1 stone = 14 lb (NIST Handbook 44, Appendix C) and 1 lb = 0.45359237 kg exactly (NIST SP 811), so 1 stone = 6.35029318 kg. Pounds may be 14 or more.
- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up.

## Worked examples

1. value = 11, lb = 4 gives result = 71.667594. Source: NIST Handbook 44 (2026), Appendix C: 1 stone = 14 lb; NIST SP 811 (2008), Appendix B.8: 1 lb = 0.45359237 kg.
2. value = 1, lb = 0 gives result = 6.350293. Source: NIST Handbook 44 (2026), Appendix C: 1 stone = 14 lb; NIST SP 811 (2008), Appendix B.8: 1 lb = 0.45359237 kg.
3. value = 10, lb = 7 gives result = 66.678078. Source: NIST Handbook 44 (2026), Appendix C: 1 stone = 14 lb; NIST SP 811 (2008), Appendix B.8: 1 lb = 0.45359237 kg.

## FAQ

### How do I convert stone and pounds to kg?

Turn the weight into pounds, then multiply by 0.45359237: kg = (st × 14 + lb) × 0.45359237. A stone is 14 lb, and a pound is exactly 0.45359237 kg.

### What is 11 stone 4 pounds in kg?

(11 × 14 + 4) × 0.45359237 = 158 × 0.45359237 = 71.667594 kg.

### What is 10 st 7 lb in kg?

147 lb × 0.45359237 = 66.678078 kg.

### How many pounds are in a stone?

14 (NIST Handbook 44). A pound is exactly 0.45359237 kg, so a stone is 14 × 0.45359237 = 6.35029318 kg.

### Can I type pounds only?

Yes. Set the stone to 0. Pounds of 14 or more are fine: 0 st 158 lb is the same as 11 st 4 lb.

## Sources

- NIST SP 811 (2008), Guide for the Use of the International System of Units, Table 5 (SI prefixes) and Appendix B.8 (factors for units listed alphabetically), retrieved 2026-10-05. https://www.nist.gov/pml/special-publication-811
- NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: British avoirdupois units, 14 pounds = 1 stone, retrieved 2026-10-05. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c