How to convert stone to kilograms
One stone equals 6.3503 kilograms, so multiply the number of stone by 6.3503:
kg = st × 6.3503
st = kg ÷ 6.3503 (1 kg = 0.157473 st)
Example: 8 st → 8 × 6.3503 = 50.8023 kg.
Going the other way, divide by 6.3503, or multiply by 0.157473; the kilograms to stone converter does it for you.
Everyday values
| Stone | Kilograms | For example |
|---|---|---|
| 8 st | 50.8023 kg | 8 stone |
| 10 st | 63.5029 kg | 10 stone |
| 11 st | 69.8532 kg | an average adult in the UK, roughly |
| 12 st | 76.2035 kg | 12 stone |
| 15 st | 95.2544 kg | 15 stone |
When you need this conversion
Stone is still the everyday unit for body weight in the UK and Ireland, usually combined with pounds: "11 stone 4" means 11 stone 4 pounds (158 lb, 71.7 kg). One stone is 14 pounds. Medical records in the UK use kilograms, so converting is common at the doctor's.
Stone to kilogram conversion table
| st | kg | st | kg |
|---|---|---|---|
| 6 st | 38.1018 kg | 16 st | 101.605 kg |
| 7 st | 44.4521 kg | 17 st | 107.955 kg |
| 8 st | 50.8023 kg | 18 st | 114.305 kg |
| 9 st | 57.1526 kg | 19 st | 120.656 kg |
| 10 st | 63.5029 kg | 20 st | 127.006 kg |
| 11 st | 69.8532 kg | 21 st | 133.356 kg |
| 12 st | 76.2035 kg | 22 st | 139.706 kg |
| 13 st | 82.5538 kg | 23 st | 146.057 kg |
| 14 st | 88.9041 kg | 24 st | 152.407 kg |
| 15 st | 95.2544 kg | 25 st | 158.757 kg |
About the units
- Stone (st): 14 pounds, exactly 6.35029318 kilograms.
- Kilogram (kg): the SI base unit of mass, defined through the Planck constant since 2019.
Both are units of weight (mass). The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many kilograms are in one stone?
One stone is 6.3503 kilograms. One kilogram is 0.157473 stone.
How do I convert stone to kilograms?
Multiply the value in stone by 6.3503. To go back, divide by 6.3503.
What is 8 st in kilograms?
8 st = 50.8023 kg.
What is 10 st in kilograms?
10 st = 63.5029 kg.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.