Note: Fractional results are rounded to the nearest 1/64. For a more accurate answer please select 'decimal' from the options above the result.
Note: You can increase or decrease the accuracy of this answer by selecting the number of significant figures required from the options above the result.
Note: For a pure decimal result please select 'decimal' from the options above the result.
The kg is defined as being equal to the mass of the International Prototype of the Kilogram (IPK), a block of platinum-iridium alloy manufactured in 1889 and stored at the International Bureau of Weights and Measures in Sèvres, France.
It is the only SI unit that is defined by a physical object rather than a fundamental physical property that can be reproduced in laboratories.
The stone is a unit of weight in the imperial system used informally in the UK and Ireland, almost exclusively as a measure of body weight. Although sanctioned by the EU for use as a supplementary unit it is essentially obsolete outside the UK and Ireland.