Petagram to Milligram

The milligram is a unit of mass equal to one thousandth of a gram (10⁻³ g) or one millionth of a kilogram.

1 mg = 0.001 g = 10⁻⁶ kg = 1,000 µg. There are 1,000 mg in 1 gram.

To convert mg to grams: divide by 1,000. To convert mg to grains: multiply by 0.01543.

Drug tablets (e.g., aspirin 325 mg), caffeine content (coffee ~95 mg/cup), sodium on food labels, and gemstone weights.

A single grain of sand weighs about 1 mg. The lethal dose of pure caffeine is roughly 10,000 mg (10 g) for an average adult.

Confusing mg with mL — milligrams measure mass, milliliters measure volume. They're only equal for water (density = 1 g/mL).

A standard paper clip weighs about 1,000 mg (1 g). Use this to visualize what a milligram fraction looks like.