The stone is a unit of weight used primarily in the United Kingdom and Ireland for measuring body weight. If you see your weight listed in "stones and pounds" and want to convert to kilograms (or vice versa), here is everything you need.
What is a Stone?
One stone equals 14 pounds or approximately 6.35 kilograms. The stone was standardised in the UK in 1835. It is rarely used outside of the UK and Ireland.
The Formula
kilograms = stone × 6.35029
pounds = stone × 14
stone = kilograms ÷ 6.35029
pounds = stone × 14
stone = kilograms ÷ 6.35029
Stone to kg Reference Table
| Stone | Kilograms | Pounds |
|---|---|---|
| 8 stone | 50.8 kg | 112 lbs |
| 9 stone | 57.2 kg | 126 lbs |
| 10 stone | 63.5 kg | 140 lbs |
| 11 stone | 69.9 kg | 154 lbs |
| 12 stone | 76.2 kg | 168 lbs |
| 13 stone | 82.6 kg | 182 lbs |
| 14 stone | 88.9 kg | 196 lbs |
| 15 stone | 95.3 kg | 210 lbs |
Stones and Pounds to kg
UK body weight is often expressed as "X stone Y pounds". To convert:
Total kg = (stone × 6.35029) + (pounds × 0.453592)
Example: 11 stone 4 pounds = (11 × 6.35029) + (4 × 0.453592) = 69.85 + 1.81 = 71.67 kg
Which Countries Use Stone?
The stone is used informally in the UK and Ireland for body weight. All official UK medical measurements use kilograms. Most scales in the UK show readings in both kg and stone/pounds.