Milligrams to Grains
A milligram is one thousandth of a gram, the standard unit for medication dosages on drug labels. A grain is about 64.8 milligrams, one of the oldest units of mass, still used for bullet and arrow weights and gunpowder charges. 1 mg equals ≈0.0154324 gr, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to mass, measured here against mass's base unit (kg) — every other mass unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
gr = mg × ≈0.0154324
mg = gr × ≈64.7989
Worked example: 5 mg × ≈0.0154324 = ≈0.0771618 gr.
Conversion table
| Milligram (mg) | Grain (gr) |
|---|---|
| 1 mg | ≈0.0154324 gr |
| 2 mg | ≈0.0308647 gr |
| 3 mg | ≈0.0462971 gr |
| 5 mg | ≈0.0771618 gr |
| 10 mg | ≈0.154324 gr |
| 20 mg | ≈0.308647 gr |
| 25 mg | ≈0.385809 gr |
| 50 mg | ≈0.771618 gr |
| 100 mg | ≈1.54324 gr |
| 250 mg | ≈3.85809 gr |
| 500 mg | ≈7.71618 gr |
| 1,000 mg | ≈15.4324 gr |
Frequently asked
- How many Grains in a milligram?
- 1 mg equals ≈0.0154324 gr.
- How do I convert Milligrams to Grains?
- Multiply the value in mg by ≈0.0154324 to get gr. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Milligram and Grain are both defined by a fixed conversion factor to mass's base unit (kg), so the result shown is exact to the precision displayed, not an approximation.