A gram (older spelling gramme) is a unit of measurement of mass, and is defined in the SI system of units as one thousandth of a kilogram. See 1 E -3 kg for comparisons with other masses.
The symbol for gram is g. Sometimes gm is incorrectly used.
A cubic centimetre (10-6 m3) of water has a mass of approximately one gram. It is approximately equal to the mass of a paper clip.
It is not an SI base unit, although it is a base unit of the cgs system of units.
See also SI prefix, conversion of units