How to convert grams to milligrams
mg = g × 1,000Multiply the value in grams by 1,000. To go the other way, multiply by 0.001 (or divide by 1,000).
A gram is larger than a milligram: one gram contains 1,000 milligrams.
Worked examples
- 1 gram1 g × 1,000 = 1,000 mg
- 5 grams5 g × 1,000 = 5,000 mg
- 10 grams10 g × 1,000 = 10,000 mg
- 20 grams20 g × 1,000 = 20,000 mg
- 100 grams100 g × 1,000 = 100,000 mg
Grams to milligrams conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Grams (g) | Milligrams (mg) |
|---|---|
| 0.1 g | 100 mg |
| 0.25 g | 250 mg |
| 0.5 g | 500 mg |
| 1 g | 1,000 mg |
| 2 g | 2,000 mg |
| 3 g | 3,000 mg |
| 4 g | 4,000 mg |
| 5 g | 5,000 mg |
| 6 g | 6,000 mg |
| 7 g | 7,000 mg |
| 8 g | 8,000 mg |
| 9 g | 9,000 mg |
| 10 g | 10,000 mg |
| Grams (g) | Milligrams (mg) |
|---|---|
| 12 g | 12,000 mg |
| 15 g | 15,000 mg |
| 20 g | 20,000 mg |
| 25 g | 25,000 mg |
| 30 g | 30,000 mg |
| 40 g | 40,000 mg |
| 50 g | 50,000 mg |
| 75 g | 75,000 mg |
| 100 g | 100,000 mg |
| 250 g | 250,000 mg |
| 500 g | 500,000 mg |
| 1,000 g | 1,000,000 mg |
About the units
Gram (g)
One thousandth of a kilogram. Recipes, nutrition labels and postal scales use grams; a US nickel weighs 5 g. One gram equals 0.001 kilograms (kg).
Milligram (mg)
One thousandth of a gram. Medication doses and vitamin contents are usually given in milligrams. One milligram equals 0.000001 kilograms (kg).
Frequently asked questions
How many milligrams are in one gram?
There are 1,000 milligrams in one gram, and this value is exact by definition.
How do I convert grams to milligrams?
Multiply the number of grams by 1,000. For example, 10 g × 1,000 = 10,000 mg.
How many grams are in one milligram?
One milligram equals 0.001 grams. That is the reverse factor, 1 ÷ 1,000.
What is 10 grams in milligrams?
10 g = 10,000 mg.
Is this g to mg converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.