Kilograms to Stone

Kilograms and stone

The kilogram is the SI base unit of mass, defined since 2019 by fixing the Planck constant. Body weight, groceries, luggage allowances and most product weights outside the US are given in kilograms.

The stone is exactly 14 pounds, or 6.35029318 kilograms. People in the UK and Ireland often state body weight in stone and pounds, for example 11 st 4 lb.

Worked example

Convert 80 kg: 80 × 0.1574730444 = 12.59784355, so 80 kilograms is 12.59784355 stone. Likewise 20 kg = 3.149460888 st.

Estimating in your head

Divide by 6.4 for a quick figure; it is off by about 0.8%. For 80 kg that gives 12.5 st, against 12.5978 exactly.

Going the other way

To convert stone to kilograms, divide by 0.1574730444 (or multiply by 6.35029318). The swap button between the boxes opens that page.

st = kg × 0.1574730444

1 kg = 1 kg and 1 st = 6.35029318 kg, both by definition, so the factor is their ratio: 0.1574730444 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.