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Grams to Grains Converter

↔ Convert gr to g instead

Common Conversions

g gr
0.01 0.154
0.065 1.003
0.1 1.543
0.325 5.016
0.5 7.716
1 15.432
2 30.865
5 77.162
10 154.324
28.35 437.5
100 1543.24

Why this conversion matters in chemistry

One gram is 15.4324 grains, exact through the international yard and pound agreement. The conversion comes up in two distinct contexts: legacy pharmacy and propellant chemistry. Translating a 0.325 g aspirin dose into the historical 5-grain notation is one direction; converting a 0.65 g detonator charge into the 10 grains a US ordnance specification might list is another. The grain is a small unit, so any practical chemistry mass becomes a large number of grains — useful when matching to legacy specifications, almost never natural for new work.

Formula

gr = g × 15.4324

Worked Examples

1 g = 15.432 gr

One gram on the apothecary scale — the conversion's calibration anchor.

0.065 g = 1.003 gr

About one grain — useful as a sanity check that the apothecary unit really is that small.

0.325 g = 5.016 gr

An aspirin tablet — the modern 325 mg dose, originally specified as 5 grains.

0.5 g = 7.716 gr

Half a gram of reagent expressed in grains — useful as a magnitude reference.

Frequently Asked Questions

How do I convert grams to grains?
Multiply by 15.4324. So 1 g becomes 15.432 grains. The factor is exact through the legal definition of the grain at 64.79891 mg.
What is a grain?
An ancient mass unit pinned to exactly 64.79891 mg (0.06480 g) by modern statute. The name comes from the mass of a single cereal grain — wheat or barley — which was historically used as a reference.
Where are grains still in use?
US pharmacy still labels some legacy doses in grains (a 5-grain aspirin tablet is the historical 325 mg). Propellant chemistry and ammunition reloading specifications also stay in grains. Almost all new chemistry runs in mg or g.
How many grains are in a gram?
Exactly 15.4324 grains per gram. The factor is locked through the SI-aligned legal definition of the grain — no rounding needed.