Formulas & exact factors
- 1 stone =
14 lb(exact) - 1 lb =
0.45359237 kg(exact) - 1 stone =
6.35029318 kg(exact)
From pounds to stones: stones = pounds ÷ 14.
Split as stones + lb: st = ⌊pounds ÷ 14⌋, lb_rem = pounds − 14×st.
From stones + lb to pounds: pounds = 14×st + lb_rem.
To kilograms: kg = pounds × 0.45359237.
Examples
154 lb → 154 ÷ 14 = 11 st (exact), kg = 154×0.45359237 = 69.85322498 kg.
12 st 5 lb → pounds = 12×14 + 5 = 173 lb → kg ≈ 78.472 kg.
FAQ
Where is “stone” used?
Primarily in the UK and Ireland for body weight. It’s not an SI unit but is widely recognized in those contexts.
Why do you show both decimal stones and stones+lb?
Decimal stones are useful for quick math (e.g., 11.5 st), while stones+lb (e.g., 11 st 7 lb) match how people report weight informally.