How to convert stone to kg
A stone is 14 pounds, and a pound is defined in law as exactly 0.45359237 kilograms. So to turn stones and pounds into kilograms you first turn everything into pounds, then multiply by 0.45359237. One stone is 6.35 kg (6.35029318 kg to be exact).
kg = (stones × 14 + pounds) × 0.45359237
Going the other way, divide kilograms by 0.45359237 to get pounds, then divide by 14. The whole number is the stones and whatever's left over is the pounds.
pounds = kg ÷ 0.45359237
stones = pounds ÷ 14 (whole number), remaining pounds = pounds − stones × 14
For a quick estimate in your head, 1 kg is about 2.2 lb and 1 stone is about 6.35 kg, so 10 stone is roughly 63.5 kg.
Worked examples
How many kg is 11 stone 7 pounds?
11 × 14 = 154 lb, plus 7 lb makes 161 lb. Then 161 × 0.45359237 = 73.03 kg.
What is 70 kg in stones and pounds?
70 ÷ 0.45359237 = 154.32 lb. That's 11 whole stones (154 lb) with 0.32 lb left over, so 70 kg is 11 st 0.3 lb, or just over 11 stone.
What is 200 lb in kg and stone?
200 × 0.45359237 = 90.72 kg. In stones, 200 ÷ 14 = 14 stone with 4 lb left over, so 14 st 4 lb.
Stone to kg chart
The table in the results shows every whole stone from 6 to 25. Here are some common body weights with half stones too.
| Stone and pounds | Kilograms | Pounds |
|---|---|---|
| 8 st | 50.8 kg | 112 lb |
| 9 st 7 lb | 60.3 kg | 133 lb |
| 10 st | 63.5 kg | 140 lb |
| 11 st 7 lb | 73.0 kg | 161 lb |
| 12 st | 76.2 kg | 168 lb |
| 13 st 7 lb | 85.7 kg | 189 lb |
| 15 st | 95.3 kg | 210 lb |
| 17 st | 108.0 kg | 238 lb |
| 20 st | 127.0 kg | 280 lb |
Why the UK still uses stones
Most people in Britain and Ireland still think about their own body weight in stones and pounds, even though shops, the NHS and most scales work in kilograms. Your GP surgery or a hospital will usually weigh you in kg, and medicine doses for children are worked out per kilogram, so it's handy to know both. In the USA, body weight is given in pounds only, so a 165 lb American weighs 11 st 11 lb.
Pounds and ounces are also still common in baking and on older recipes. There are 16 ounces in a pound, and one ounce is 28.35 g. Our cooking conversion calculator handles cups, ounces and grams for recipes.
Tips for converting weight
- Don't mix up 11.5 stone and 11 st 5 lb. 11.5 stone is 11 st 7 lb (73.03 kg), while 11 st 5 lb is 72.12 kg. Type decimal stones in the stones box and leave pounds at 0.
- Pounds over 14 are fine. If you enter 10 st 20 lb the calculator treats it as 11 st 6 lb.
- Weight loss: losing 1 stone is losing 6.35 kg. The NHS suggests aiming for 0.5 kg to 1 kg (about 1 lb to 2 lb) a week if you're trying to lose weight.
- Health checks: to see if your weight is healthy for your height, use the BMI calculator, which accepts stones or kilograms. If you need to convert your height first, try the cm to feet calculator.
Frequently asked questions
How many kg is 1 stone?
One stone is 6.35 kg (6.35029318 kg exactly), because a stone is 14 lb and each pound is 0.45359237 kg.
How do I convert stones and pounds to kg?
Multiply the stones by 14, add the pounds, then multiply by 0.45359237. For example, 11 st 7 lb is 161 lb, which is 73.03 kg.
What is 70 kg in stone?
70 kg is 154.3 lb, which is 11 st 0.3 lb, so just over 11 stone.
How many pounds are in a stone?
There are 14 pounds in a stone, so 10 stone is 140 lb and 15 stone is 210 lb.
Is 11.5 stone the same as 11 stone 5?
No. 11.5 stone is 11 st 7 lb (73.03 kg), because half a stone is 7 lb. 11 st 5 lb is 72.12 kg.
Last reviewed October 2026 using 2026/27 figures. This calculator gives an estimate for guidance only.