nLab kilogram

The kilogram (kilogramme, $kg$) is a unit of mass. It is $1000$ grams (grammes, $g$).

The kilogram is defined by setting the Planck constant to be exactly

$$6.62607015\times 10^{-34} kg\cdot m^2\cdot s^{-1}$$

and using the previously given definitions of the second and the metre.

The kilogram used to be defined as the mass of a certain physical object, le Grand K, kept by the BIPM in Paris.

References

• Wikipedia, Kilogram