Convert milligrams to grams instantly. Enter a value below, or use the formula and reference table further down the page.
In practice
Milligrams to grams divides by 1,000, because a milligram is a thousandth of a gram. It is used to make sense of dosage and nutrition figures: 500 mg is 0.5 g, and 2,000 mg is 2 g. Food labels often list salt, vitamins and caffeine in milligrams while the main nutrients are in grams, so converting helps you compare totals — 400 mg of caffeine, for example, is only 0.4 g. As ever with medicines, follow the label or your pharmacist rather than your own calculation.
How to convert milligrams to grams
Multiply the value by 0.001.
g = mg × 0.001Example: 10 mg = 0.01 g.
Milligrams to Grams conversion table
| Milligrams (mg) | Grams (g) |
|---|---|
| 1 mg | 0.001 g |
| 2 mg | 0.002 g |
| 3 mg | 0.003 g |
| 4 mg | 0.004 g |
| 5 mg | 0.005 g |
| 10 mg | 0.01 g |
| 15 mg | 0.015 g |
| 20 mg | 0.02 g |
| 25 mg | 0.025 g |
| 50 mg | 0.05 g |
| 100 mg | 0.1 g |
Frequently asked questions
How many grams is 1 milligram?
1 milligram equals 0.001 grams.
What is the formula to convert mg to g?
To convert mg to g, multiply the value by 0.001. The full formula is: g = mg × 0.001.
How do I convert grams back to milligrams?
Use the same calculator above and type your value into the grams field instead — it converts in both directions. Or use the reverse formula: mg = g ÷ 0.001.
Is the mg to g conversion exact?
The conversion factor used here (0.001) is the standard internationally defined value. Results on this page are rounded to four decimal places for readability.