Unit converter

Stone to kilograms.

Convert st to kg and kg to st. Type in either box and the other follows. Stone is a UK-only unit for body weight; hospital records and airline allowances are in kilograms.

st → kgExact definition
Stone to kilograms — common values, to 6 significant figures.
stkg
1 st6.35029 kg
2 st12.7006 kg
5 st31.7515 kg
7 st44.4521 kg
8 st50.8023 kg
9 st57.1526 kg
10 st63.5029 kg
11 st69.8532 kg
12 st76.2035 kg
13 st82.5538 kg
14 st88.9041 kg
15 st95.2544 kg
16 st101.605 kg
18 st114.305 kg
20 st127.006 kg
1 st=6.35029318 kg 1 kg=0.1574730444 st

Definitions

  • The stone is 14 pounds, exactly 6.350 293 18 kg. UK body weight is normally quoted as stone and pounds — 12 st 4 lb, not 12.29 st.
  • 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 = 6.35029318 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: how many kilograms in a stone (6.35029), how many stone in a kilogram (0.157473), and what 12 st is in kilograms (76.2035 kg).