Grams to Milligrams converter

To convert grams to milligrams, enter the value in the first field. The result in milligrams is calculated automatically using the exact conversion factor.

1 g = 1000 mg
1 mg = 0.001 g

Formula: mg = g × 1000
g = mg × 0.001

Definitions: 1 g = 0.001 kg; 1 mg = 0.001 g

The gram (g) is one thousandth of a kilogram. It is used for food portions, recipe ingredients, nutrition labels and small items such as letters and jewelry.

The milligram (mg) is one thousandth of a gram. It is the standard unit for doses of medicines and supplements, and for nutrients such as sodium and caffeine on food labels.

See the conversion table with commonly used values, handy for quick reference or study.