Stone to Kilograms (st to kg)

Formula: kg = st × 6.35029318

stone to kg chart

Reading the result as stone and pounds

Weight in stone is normally spoken as stone and pounds rather than as a decimal. Keep the whole number as stone and multiply the remainder by 14, because a stone is 14 pounds:

70 kg = 11.0231 st
whole stone      = 11
0.0231 x 14      = 0.32 pounds
so 70 kg is about 11 st 0 lb

Multiplying the remainder by 10 is the common error here — it treats the decimal as if stone were a metric unit, and it can be out by several pounds.

Related: cm to inches · kg to lbs · meters to feet · Celsius to Fahrenheit

Stone to Kilograms at a glance

Stone is a UK and Irish unit for body weight; kilograms are the SI unit used for medical dosing and everywhere outside those countries.

Both directions from one number

You only need to remember one factor, because the reverse is its reciprocal:

kg = st × 6.35029318
st = kg × 0.1575   (or divide by 6.35029318)

If a result looks about right but is off by a large multiple, you have almost certainly multiplied where you should have divided — checking the direction against the table above catches it immediately.

Rounding, and how precise to be

Converting does not create accuracy that was not in the original measurement. If someone tells you a distance in whole stone, the converted figure is only as good as that starting estimate — quoting it to four decimal places implies a precision nobody measured.

A practical rule: keep roughly the same number of significant figures you started with, and round only at the end. Rounding at each intermediate step compounds the error, which is how a chain of conversions drifts away from the right answer.

TryCalculatingNow