Convert Milligrams to Grains
Convert Milligrams (mg) to Grains (gr) instantly and accurately.
Conversion Formula
gr = mg × 0.01543235835
About Milligrams
A milligram (mg) is one thousandth of a gram (10⁻³ g). It is the primary unit for pharmaceutical dosing: aspirin tablets are typically 500 mg, ibuprofen 200-400 mg, and melatonin supplements 0.5-10 mg. Precious metal assay results and alloy compositions are specified in milligrams per kilogram (mg/kg = ppm). Nutritional labels worldwide list mineral content in milligrams - the recommended daily intake of iron is 8-18 mg, calcium 1000 mg, and sodium under 2300 mg. A grain of rice weighs about 25-30 mg, and a medium eyelash approximately 0.1 mg.
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.
Quick Reference Table
| Milligrams (mg) | Grains (gr) |
|---|---|
| 1 mg | 0.0154324 gr |
| 2 mg | 0.0308647 gr |
| 5 mg | 0.0771618 gr |
| 10 mg | 0.154324 gr |
| 25 mg | 0.385809 gr |
| 50 mg | 0.771618 gr |
| 100 mg | 1.54324 gr |