Convert Grains to Slugs
Convert Grains (gr) to Slugs (slug) instantly and accurately.
Conversion Formula
slug = gr × 4.440135739e-6
About Grains
A grain (gr) is the smallest unit in both the avoirdupois and troy weight systems, equal to exactly 64.79891 milligrams. Originally defined as the mass of a single grain of barley or wheat from the middle of an ear, it has been a standard of weight since ancient times. Today, grains are used to weigh gunpowder charges and bullets (a standard .308 rifle bullet weighs 168 gr), pharmaceutical preparations in apothecary compounding, and the fineness of gold alloys. Arrowhead and fishing hook weights are also specified in grains.
About Slugs
A slug is a unit of mass in the British imperial and US customary foot-pound-second (FPS) engineering system, equal to the mass that accelerates at 1 foot per second squared under a force of 1 pound-force - approximately 14.594 kg. The slug was introduced to simplify dynamics calculations in engineering: using slugs ensures that F = ma holds without unit conversion factors when force is in pounds-force and acceleration in ft/s². Aerospace engineers and mechanical engineers working in US customary units use slugs for aircraft mass, structural dynamics, and ballistic calculations.
Quick Reference Table
| Grains (gr) | Slugs (slug) |
|---|---|
| 1 gr | 4.44 × 10-6 slug |
| 2 gr | 8.88 × 10-6 slug |
| 5 gr | 2.22 × 10-5 slug |
| 10 gr | 4.44 × 10-5 slug |
| 25 gr | 0.000111003 slug |
| 50 gr | 0.000222007 slug |
| 100 gr | 0.000444014 slug |