The exact factor
A stone is a UK and Irish unit of body weight equal to 14 pounds, fixed by the pound being exactly 0.45359237 kg. That makes one stone 6.35029 kg. Multiply by 6.35 in your head for a close estimate.
Stone and pounds is not decimal stone
British weight is usually spoken as "11 stone 7," meaning 11 whole stone plus 7 loose pounds — not 11.7 stone. The leftover runs 0 to 13 pounds, then rolls over to the next stone. Convert the pounds part at 14 to the stone, not as a decimal.
"11 stone 7" (73.0 kg) and "11.7 stone" (74.3 kg) are different weights — the loose pounds go up to 13, not 9, before the next stone.
Quick reference — body weight
| Stone | Kilograms | Pounds |
|---|---|---|
| 8 st | 50.8 kg | 112 lb |
| 10 st | 63.5 kg | 140 lb |
| 11 st | 69.9 kg | 154 lb |
| 12 st | 76.2 kg | 168 lb |
| 13 st | 82.6 kg | 182 lb |
| 15 st | 95.3 kg | 210 lb |
Each extra stone adds 6.35 kg; each extra pound adds 0.454 kg.
Common questions
How many kg are in a stone?
One stone is exactly 6.35029 kilograms, because a stone is 14 pounds and each pound is 0.45359237 kg. For a quick estimate, multiply stone by 6.35.
How do I convert stones and pounds to kg?
Turn the whole weight into pounds first: multiply the stone by 14 and add the loose pounds. Then multiply that total by 0.453592. So 11 st 7 lb is 161 lb, which is about 73.0 kg.
What is 12 stone in kilograms?
12 stone is 76.2 kg (12 times 6.35029). Add any extra pounds separately at 0.4536 kg each.
