UK weight-loss calculator
Stone to kg converter
Convert stone and pounds to kilograms, useful for medical forms, travel and anything that expects metric. Type into either box to convert both ways.
Updated
st lb = kg
Displayed values are rounded for readability, but the arithmetic uses the full precision of the internationally defined factors, a pound is exactly 0.45359237 kg and a stone is exactly 14 pounds, so converting back and forth will not drift.
Stone and pounds to Kilograms
70 kg
11 st 0.3 lb converts to the figure on the left, exactly. Nothing in it is an approximation.
About stone and pounds and kilograms
Convert your stone and pounds into total pounds first, then multiply by 0.45359237. So 12 stone 4 pounds is (12 × 14) + 4 = 172 pounds, which is 78.0 kg.
Doing it in that order matters. Converting the stone and the pounds separately and adding the results gives the same answer, but converting "12.4 stone" as a decimal does not, that would be 12 stone 5.6 pounds, which is a different weight.
The conversion
kg = ((stone × 14) + pounds) × 0.45359237The table below is generated from the same conversion used by the tool above, so the two always agree.
| Stone and pounds | Kilograms |
|---|---|
| 7 st 0 lb | 44.5 kg |
| 8 st 0 lb | 50.8 kg |
| 9 st 0 lb | 57.2 kg |
| 10 st 0 lb | 63.5 kg |
| 11 st 0 lb | 69.9 kg |
| 12 st 0 lb | 76.2 kg |
| 13 st 0 lb | 82.6 kg |
| 14 st 0 lb | 88.9 kg |
| 15 st 0 lb | 95.3 kg |
| 16 st 0 lb | 101.6 kg |
| 17 st 0 lb | 108 kg |
| 18 st 0 lb | 114.3 kg |
| 19 st 0 lb | 120.7 kg |
| 20 st 0 lb | 127 kg |
| 21 st 0 lb | 133.4 kg |
| 22 st 0 lb | 139.7 kg |
A note on rounding
Conversions are shown rounded for readability, weights to a tenth of a unit, heights to the nearest inch or centimetre. The underlying arithmetic uses the full precision of the internationally defined factors, so repeatedly converting back and forth will not drift.
Bathroom scales themselves are usually accurate to within a few hundred grams at best, and body weight varies by a kilogram or more across a single day. That variation is far larger than any rounding here.
Every stone, worked out
A page for each whole stone, with the half either side of it and what that weight comes to at eight common heights.
- 6 stone38.1 kg
- 7 stone44.5 kg
- 8 stone50.8 kg
- 9 stone57.2 kg
- 10 stone63.5 kg
- 11 stone69.9 kg
- 12 stone76.2 kg
- 13 stone82.6 kg
- 14 stone88.9 kg
- 15 stone95.3 kg
- 16 stone101.6 kg
- 17 stone108 kg
- 18 stone114.3 kg
- 19 stone120.7 kg
- 20 stone127 kg
- 21 stone133.4 kg
- 22 stone139.7 kg
- 23 stone146.1 kg
- 24 stone152.4 kg
- 25 stone158.8 kg
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Frequently asked questions
How do I convert stone to kg?
Multiply your stone by 14 to get pounds, add any extra pounds, then multiply the total by 0.45359237. Or multiply your stone by 6.35029318 and add the pounds converted separately.
Why do medical forms ask for kilograms?
Kilograms are the standard unit in clinical practice, and medication doses in particular are often calculated per kilogram of body weight. Converting accurately matters more in that context than in everyday use.
Important information
The calculators on this site provide general information and estimates. They are not medical advice and they do not diagnose any condition.
Everyone is different, and individual energy needs vary for reasons these equations cannot capture. If you have a health condition, take medication, are pregnant or breastfeeding, or have any concerns about your weight, speak to your GP, pharmacist or a registered dietitian.