Unit converter
Stone and pounds to kilograms.
Convert st + lb to kg and kg to st + lb. Type in either box and the other follows. Enter it as "12 st 4 lb" or "12 4". Hospital notes, airlines and gyms all want the kilograms.
| st + lb | kg |
|---|---|
| 8 st 0 lb | 50.8023 kg |
| 9 st 0 lb | 57.1526 kg |
| 10 st 0 lb | 63.5029 kg |
| 11 st 0 lb | 69.8532 kg |
| 12 st 0 lb | 76.2035 kg |
| 13 st 0 lb | 82.5538 kg |
| 14 st 0 lb | 88.9041 kg |
| 15 st 0 lb | 95.2544 kg |
| 16 st 0 lb | 101.605 kg |
| 18 st 0 lb | 114.305 kg |
- The whole stone are kept whole and only the remainder becomes pounds, which is why the answer reads the way people say it.
Definitions
- Stone and pounds together, the way UK body weight is quoted. Fourteen pounds to the stone.
- The kilogram is the SI base unit of mass, defined since 2019 by fixing the Planck constant rather than by a metal cylinder in Paris.
- This conversion is exact by definition. 1 st 0 lb = 6.35029 kg.
- Everything here is mass, not force. The pound is defined as exactly 0.453 592 37 kg, so pound-to-kilogram conversion is exact.
How it works
One direction multiplies and the other divides by the same number, so nothing is lost by going back and forth.
The value passes through kg, the unit every other mass & weight unit on the site is defined against, rather than a number written into this page on its own. That is why the figure here, the figure in the table above and the general mass & weight converter always agree.
Display precision limits significant figures rather than decimal places, because one fixed number of decimals is useless across a range this wide. Very large and very small results switch to scientific notation with a proper superscript exponent. The editable box always holds a plain number at full working precision, so you can carry on from either side.
Common questions this answers: what 12 st 4 lb is in kilograms (78.0179 kg), how many pounds make a stone (14), and how to type it — "5 st 9 lb" or just "5 9" are all accepted.
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