Convert stone to kilograms — and back — using the exact definition (1 st = 14 lb = 6.35029318 kg). Loads with st → kg preselected, and the FAQ covers the stones-and-pounds compound format (“12 st 6 lb”) that plain converters fumble.
The formula
kg = stones × 6.35029318 · stones = kg × 0.15747304. For st + lb weights: kg = (stones × 14 + pounds) × 0.45359237. Mental math: 6.35 kg per stone — call it “six and a third”.
Body-weight ladder
| stone | kg | stone | kg |
|---|---|---|---|
| 8 | 50.8 | 13 | 82.6 |
| 9 | 57.2 | 14 | 88.9 |
| 10 | 63.5 | 15 | 95.3 |
| 11 | 69.9 | 16 | 101.6 |
| 12 | 76.2 | 18 | 114.3 |
| 12 st 6 | 78.9 | 20 | 127.0 |
The UK body-weight unit
Stone survives almost exclusively as spoken body weight in Britain and Ireland — medical records are metric, gym equipment is metric, but the answer to “what do you weigh?” comes in stones. That mismatch makes this the conversion of GP visits, fitness apps set to kg, and “losing a stone” resolutions (6.35 kg, or exactly 14 lb). US readers rarely meet the stone at all — American body weight runs straight through the pounds to kg converter, and metric-first readers through kg to lbs.
Private by design
Converted on your device as you type — nothing transmitted, nothing stored. All 46 units live in the unit converter.