About the mg to g calculation
One milligram is exactly 0.001 grams, so converting between them is a single multiplication. Enter any value above and the result updates as you type. The usual unit for medication doses and nutrient quantities. The everyday cooking and food-labelling unit in metric countries.
Formula
g = mg × 0.001
1 mg = 0.001 g
1 g = 1,000 mgWorked example
To convert 500 mg, multiply by 0.001: 500 × 0.001 = 0.5 g.
Frequently asked questions
How many grams are in a milligram?
There are 0.001 grams in one milligram. To convert any amount, multiply the number of milligrams by 0.001.
How do I convert grams back to milligrams?
Divide instead of multiplying, or equivalently multiply by 1,000. One gram is 1,000 milligrams.
Is this conversion exact?
Yes. Since the international agreement of 1959, the relationship between milligrams and grams is defined exactly rather than measured, so the only rounding here is in how many decimal places we show.
Where is each of these units used?
Milligrams: the usual unit for medication doses and nutrient quantities. Grams: the everyday cooking and food-labelling unit in metric countries.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units