Milligram (mg)

Definition

One thousandth of a gram (10⁻⁶ kg).

History

The milligram is one thousandth of a gram, part of the decimal metric system. Its small size suits doses and trace amounts.

Where it is used

Milligrams are the everyday unit for medication doses and for nutrients on food labels.

Typical uses include medication doses, nutrition labels.

Conversion pages

These pages convert milligram to or from another unit in weight.

No conversion pages use this unit yet.

Other Weight units

• Kilogram (kg)
• Gram (g)
• Pound (lb)
• Ounce (oz)
• Stone (st)
• Microgram (mcg)
• Tonne (t)

Sources

• BIPM SI BIPM, The International System of Units (SI), 9th ed. (2019) · Dataset reviewed Nov 11, 2026