Guide · Published October 26, 2026 · By the site maintainer
Stone, kilograms, and pounds: converting body weight
One stone is exactly 14 pounds, which is 6.35029 kilograms. To convert a weight like 11 stone 4 pounds to kilograms, turn it into total pounds first — 11 × 14 + 4 = 158 lb — then multiply by 0.45359237, giving 71.67 kg. To convert back, divide kilograms by 0.45359237 to get pounds, then split into stone and leftover pounds.
The stone survives almost exclusively for body weight in the United Kingdom and Ireland. Nobody ships freight or sells flour by the stone anymore, but a British person who cannot tell you their weight in kilograms will state it in stone and pounds without hesitation. Anyone reading a UK health record, a British sports roster, or a grandparent's diary needs the conversion.
Stone and pounds to kilograms, step by step
- Multiply the stone by 14. That is the pounds in the stone part.
- Add the extra pounds. Now you have the total weight in pounds.
- Multiply by 0.45359237. One pound is exactly 0.45359237 kg, so the result is exact before rounding.
Worked example: 12 stone 9 pounds. Twelve stone is 168 lb; plus 9 is 177 lb; 177 × 0.45359237 = 80.29 kg. The kilograms and pounds converter does step three for any total you give it.
Kilograms to stone and pounds, step by step
- Divide kilograms by 0.45359237 (or multiply by 2.20462) to get total pounds.
- Divide the pounds by 14. The whole number is the stone.
- The remainder is the pounds that follow the stone in the usual way of writing it.
Worked example: 75 kg. Dividing by 0.45359237 gives 165.35 lb. Dividing by 14 gives 11 stone with a remainder of 165.35 − 154 = 11.35 lb, so 75 kg is 11 stone 11 pounds to the nearest pound.
Body weight reference table
| Stone | Pounds | Kilograms |
|---|---|---|
| 7 st | 98 lb | 44.45 kg |
| 8 st | 112 lb | 50.80 kg |
| 9 st | 126 lb | 57.15 kg |
| 10 st | 140 lb | 63.50 kg |
| 11 st | 154 lb | 69.85 kg |
| 12 st | 168 lb | 76.20 kg |
| 13 st | 182 lb | 82.55 kg |
| 14 st | 196 lb | 88.90 kg |
| 15 st | 210 lb | 95.25 kg |
| 16 st | 224 lb | 101.60 kg |
| 17 st | 238 lb | 107.95 kg |
| 18 st | 252 lb | 114.31 kg |
| 19 st | 266 lb | 120.66 kg |
| 20 st | 280 lb | 127.01 kg |
For a weight between rows, add 0.4536 kg for each extra pound above the row. Eleven stone 7 pounds is the 11 st row plus 7 lb: 69.85 + 3.18 = 73.03 kg.
The decimal-stone mistake
Scales and apps that display stone as a decimal cause a quiet error. A reading of 11.4 stone does not mean 11 stone 4 pounds. The .4 is four tenths of a full stone, and a full stone is 14 pounds, so 11.4 stone is 11 stone and 0.4 × 14 = 5.6 pounds — 72.39 kg, which most people would state as 11 stone 6 pounds. Reading the decimal as pounds understates the weight, and the error grows with the decimal: 11.9 stone is nearly 11 stone 13 pounds, not 11 stone 9.
The reverse mistake happens too. If you need to enter 11 stone 4 pounds into a system that wants decimal stone, the entry is 11 + 4/14 = 11.29 stone, not 11.4. When in doubt, convert to total pounds or kilograms first — both are single numbers that cannot be misread. Our rounding guide covers when to round the final figure.
Where the stone is still used
- Personal weight in the UK and Ireland: The everyday unit, even though official medicine records kilograms.
- British and Irish sport: Boxers, jockeys, and darts players are traditionally announced in stone and pounds.
- Older records elsewhere: Historical documents from across the former British sphere may state weights in stone; the stone was legally defined at different values in different trades centuries ago, but the modern stone has been 14 pounds since the nineteenth century.
Strictly speaking, all three units here measure mass rather than weight, a distinction our mass vs. weight guide explains. For every practical purpose — a health form, a luggage check, a training log — converting carefully and rounding once at the end is all the precision the subject needs.