Stone to kilograms converter

How to convert stone to kg

Multiply stone by 6.35029318. A stone is 14 lb and a pound is exactly 0.45359237 kg, so 1 st = 6.35029318 kg, unrounded. 11 st = 69.85322498 kg, about 69.9 kg. Use it for body weights in stone, still common in the UK and Ireland.

Stone and pounds to kg

Body weight in stone often comes with extra pounds, such as 11 st 5 lb. Convert the whole reading to pounds, then to kilograms:

1. 11 st × 14 = 154 lb, plus 5 lb = 159 lb.
2. 159 × 0.45359237 = 72.12118683 kg.

As one formula: kg = (14 × stone + pounds) × 0.45359237. The stone, pound and ounce relationships are listed in the Government of Gibraltar's measurement tables, Schedule 1, Part V.

11.5 stone is not 11 st 5 lb

A decimal is a fraction of a stone, and half a stone is 7 lb. So 11.5 st means 11 st 7 lb, or 161 lb, which is 73.02837157 kg. Reading it as 11 st 5 lb loses 2 lb, about 0.91 kg.

To enter 11 st 5 lb as a single stone value, type 11+5/14, which is 11.357 st.

Stone to kilograms chart

Every value is exact, and each extra stone adds 6.35029318 kg. A stone is heavier than a kilogram, so the kilogram figure is always the larger number: a result near 1.73 for 11 st means the kg-to-stone factor, 0.15747, was applied instead.

Is 6.35 close enough?

Yes for everyday use. Multiplying by 6.35 is only 0.005% low: 11 st gives 69.85 kg against 69.853 kg. Rounding the factor to 6.4 or 6.3 is about 0.8% off, roughly 0.75 kg at 15 st.

Weight changes in stone

A change converts the same way, sign included: −0.5 st is −3.17514659 kg, so losing half a stone means about 3.2 kg less. Losing a full stone means 6.35 kg less.

Related converters

For the opposite direction, use kg to stones. Stones to lbs gives the total in pounds, and lbs to kg converts a pound total directly. To use the result in a body mass index, try the BMI calculator.