Convert grams to grains

Divide the number of grams by 0.06479891 and you have the mass in grains. Eight grams comes out at 123.46 grains.

Formula: grains = grams ÷ 0.06479891

Multiplication gives the same answer and reads more easily, because one gram is 15.4324 grains[1]. Written as grains = grams × 15.4324 it gives the same figure and covers anything a kitchen scale will show you.

Take three example bullet masses written in grams. Eight grams is 123.46 grains. Nine and a half grams gives 146.61 grains. Eleven and a half grams comes to 177.47 grains. Each extra gram adds 15.43 grains to the result. Between eight and eleven and a half grams the difference therefore comes to 54.01 grains. That sum is useful when the load table comes from an American manual and the scale on the bench reads grams.

The arithmetic is exact both ways, because the grain has a value fixed directly in metric terms. The grains to grams converter covers the opposite direction.

A gram is a thousandth of a kilogram, and the kilogram is the base unit of mass in the SI system. The rest of the notation follows from that: a thousand grams make a kilogram and a thousand milligrams make a gram — the grams to kilograms converter handles the first of those steps and the grams to milligrams converter the second.

The grain comes from a system other than SI. It belongs to the English system of measurement and weighs 64.79891 milligrams[1], so a single gram holds 15.43 of them. Its symbol is gr, and the name comes from the cereal seed whose mass once served as the reference[2].

The grain is useful wherever a gram is too coarse and a milligram too fine. Easton, which makes arrow shafts, states shaft mass as grains per inch and notes that the figure leaves out the point, the nock, the insert and the fletchings[3].

The same scale applies in the jewellery trade. A metric carat is 200 milligrams, or 3.09 grains, and a quarter carat carries its own name in the pearl trade: the pearl grain[4]. The switch below the converter fields moves the calculation to that value.

Because Europeans stay with the metric system and state ammunition mass in grams, while Anglo-American makers give bullet weight in grains[5].

In Europe the rules for proof testing firearms and ammunition are set by C.I.P., the Permanent International Commission for the Proof of Small Arms, founded on 15 July 1914. Its members are Austria, Belgium, Chile, the Czech Republic, Finland, France, Germany, Hungary, Italy, Portugal, Russia, Serbia, Slovakia, Spain, the United Arab Emirates and the United Kingdom[6].

The American counterpart is SAAMI, an association of manufacturers. C.I.P. decisions carry the force of law in member states, while SAAMI issues recommendations to makers[7].

Browning converts the masses of its own cartridges in both directions. It describes its BXR 30-06 Spr. cartridge as 155 grains, which is 10.04 grams. For the BXS 300 WM it gives 180 grains, which is 11.66 grams. For the BXC 308 Win. it starts from the metric side and prints 10.89 grams, which is 168 grains[5].

In a spreadsheet the whole swap is one formula. The function is called CONVERT and its syntax is CONVERT(number,from_unit,to_unit)[9], so grams to grains reads =CONVERT(A1,"g","grain").