How do you convert grains to slugs?

One grain equals 4.440 x 10-6 slugs. Multiply grains by this factor to get slugs.

What is the grain used for today?

The grain remains standard in ammunition manufacturing (bullet and powder weights), archery (arrow component weights), and some pharmaceutical contexts. It is identical across troy, avoirdupois, and apothecary systems.

Is this conversion commonly needed?

Only in specialized contexts. The grain serves ammunition and pharmacy; the slugs serves different domains. Their conversion is mainly for historical research or reference tables.

Grains to Slugs (gr to slug) Converter

1 gr = 0.000004 slug

1 Grain equals 0.000004 Slugs (1 gr = 0.000004 slug). Convert Grains to Slugs with formula, table, and examples.

One grain equals approximately 4.440 x 10^-6 slugs. The slug (about 14.594 kg) contains roughly 225,218 grains. The grain measures ammunition; the slug measures mass in American physics. Both serve engineering at vastly different scales.

How to Convert Grains to Slugs

slug = gr × 0.0000044401

Multiply the value in Grains by 0.0000044401

Take your value in Grains
Multiply by 0.0000044401
Read the result in Slugs

Common Grains to Slugs Conversions

Grains (gr)	Slugs (slug)	Status
1,000 gr	0.0044401357 slug
7,000 gr	0.03108095 slug
10,000 gr	0.0444013572 slug
50,000 gr	0.222006786 slug
100,000 gr	0.444013572 slug
500,000 gr	2.2200678598 slug
1,000,000 gr	4.4401357197 slug
5,000,000 gr	22.2006785985 slug

Good to Know About Grains to Slugs Conversion

The grain is one of the oldest continuously used weight units, traceable to Mesopotamian barley seeds around 3000 BCE. Through 5,000 years across Babylonian, Egyptian, Greek, Roman, and English civilizations, it retained its essential character: the weight of a single cereal seed. Today it measures bullets, but its agricultural soul endures in its name.

Grains to Slugs: What You Need to Know

The grain's universality across English weight systems makes it the natural reference for conversions to slugs. Whether weighing ammunition, pharmaceutical ingredients, or precious metals, the grain provides a consistent 64.80-milligram reference that all three traditional English systems share.

What is a Grain? gr

A grain is a unit of mass equal to exactly 64.79891 milligrams. It is the same in the avoirdupois, troy, and apothecaries' systems, derived from the 1959 international agreement defining the pound as exactly 0.45359237 kilograms.

Imperial Troy Apothecaries ammunition weight bullet measurement historical pharmacy

Learn more about Grain →

What is a Slug? slug

A slug is a unit of mass in the imperial system used in physics and engineering. It equals approximately 14.593903 kilograms, derived from the pound-force, standard gravity, and the foot.

Imperial physics engineering aerospace

Learn more about Slug →

Going the other way? Use our Slugs to Grains converter.

Grains to Slugs FAQ

One grain equals 4.440 x 10^-6 slugs. Multiply grains by this factor to get slugs.
The grain remains standard in ammunition manufacturing (bullet and powder weights), archery (arrow component weights), and some pharmaceutical contexts. It is identical across troy, avoirdupois, and apothecary systems.
Only in specialized contexts. The grain serves ammunition and pharmacy; the slugs serves different domains. Their conversion is mainly for historical research or reference tables.

Non-Frequently Asked Questions About Grains to Slugs

Questions nobody should ask - but someone did.

Each SRB contained about 500,000 kg of solid propellant - roughly 7.7 billion grains or 34,267 slugs. The grain measures propellant in each cartridge; the slug measures the booster's contribution to F=ma.
Technically mass (amount of matter). In practice, people treat it as weight (gravitational force). The distinction matters only in physics, where the slug exists specifically to separate mass from weight. At grain scale, the difference is about 0.3% depending on altitude.
One slug is about 225,218 grains. If each were a 64.8 mg bead, lining them up would create a chain about 1.1 kilometers long. Assembling it grain by grain would be spectacularly tedious.