Convert grams to milligrams
Enter a value in grams to convert it to milligrams.
grams to milligrams reference
| grams | milligrams |
|---|---|
| 1 g | 1000 mg |
| 2 g | 2000 mg |
| 5 g | 5000 mg |
| 10 g | 10000 mg |
| 25 g | 25000 mg |
| 50 g | 50000 mg |
| 100 g | 100000 mg |
The conversion factor
One gram is 1000 milligrams. So to convert, multiply your figure in grams by 1000. To go the other way, multiply milligrams by 0.001, or use the milligrams to grams converter.
Doing it in your head
For a quick estimate, round the factor: roughly "times 1000". Use the exact converter above when the number matters.
Where this conversion comes up
Recipes, shipping and luggage limits, body weight, and nutrition labels.
See the common unit conversions cheat sheet for the factors worth memorising.
Related tools
Frequently asked questions
How many milligrams are in a gram?
1 gram = 1000 milligrams.
What is the formula to convert grams to milligrams?
Multiply the number of grams by 1000. To go back the other way, multiply milligrams by 0.001.
What is 10 grams in milligrams?
10 grams = 10000 milligrams. The reference table below lists more common values.
Is this converter accurate?
It uses the internationally defined conversion factors and computes at full floating-point precision, then rounds only the displayed result. For everyday purposes it is exact; for legal, engineering or scientific work, confirm the required number of significant figures.
Does it work offline?
Yes. The conversion runs in your browser with no server call, so it keeps working with no connection, and nothing you enter is uploaded.
Last reviewed: September 2026. Figures and formulas are checked against their published sources; see the site's data notes.