# How to convert stone to kg?

Converts stone (st) to kilograms (kg) and back, with the exact unit definitions.

- Page: https://www.acalculator.org/convert/stone-to-kg
- JSON spec: https://www.acalculator.org/convert/stone-to-kg.json
- Version: 707ed823c332

## Default answer

Example with the default inputs (Stone (st) 1): 1 st = 6.350293 kg.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Stone (st) | The amount in stone to convert. |
| result | Kilograms (kg) | The same amount in kilograms. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Stone (st) | The amount in stone to convert. |
| result | Kilograms (kg) | The amount in kilograms. |

## Method

kg = st × 6.35029318

## Assumptions

- 1 stone = 6.35029318 kilograms, from the exact definitions in NIST SP 811.
- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up.

## Worked examples

1. value = 1 gives result = 6.350293. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
2. value = 10 gives result = 63.502932. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
3. result = 63.502932 gives value = 10. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.

## FAQ

### How many kilograms are in a stone?

1 stone is 6.350293 kilograms, from the exact unit definitions (NIST SP 811).

### How do I convert stone to kg?

Multiply by 6.350293: kg = st × 6.35029318. For example, 1 st × 6.350293 = 6.350293 kg.

### How do I convert kg back to stone?

Multiply by 0.157473, or type the kilograms into the second box and the converter works it out. 1 kilogram is 0.157473 stone.

### 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.

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

Use the stone and pounds to kg converter, or turn the pounds into stone first: 11 st 4 lb is 11 + 4 ÷ 14 = 11.285714 stone, which is 71.667594 kg.

### What is 10 stone in kg?

10 × 6.35029318 = 63.5029318 kg, shown as 63.502932 kg.

## 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