Grain to Grams Converter

One grain equals exactly 0.06479891 grams, or about 64.8 milligrams. The grain is a very old unit, originally based on the weight of a single barley or wheat grain, and it is still standard for bullets, gunpowder, and arrow weights, plus some pharmacy doses.

Multiply the grain value by 0.06479891: grams = grains x 0.06479891. To go back, divide by that factor (one gram is about 15.43 grains). This converter also shows milligrams and ounces.

The grain is a small, precise unit that suits the mass of projectiles and powder charges. A common 9mm bullet weighs 115 or 124 grains, and a 5.56mm bullet about 55 grains. Reloaders measure powder in grains for the same reason.

There are exactly 7000 grains in one avoirdupois pound, which is 453.59 grams. There are 437.5 grains in an ounce. The grain is the smallest unit shared by the avoirdupois, troy, and apothecary systems.