mililitre

A millilitre, sometimes spelled millilitre in British English, is a unit of volume in the metric system. It is defined as one thousandth of a litre. The standard symbol is mL, though ml is also commonly seen. In terms of cubic measures, one millilitre is equal to one cubic centimetre (cm³).

Relation to other units: one litre equals 1000 millilitres, and one cubic metre equals 1000 litres, or 1,000,000 millilitres. Because the millilitre is a submultiple of the litre, it is frequently used for measuring small volumes in science, medicine, cooking, and beverages.

Usage and context: millilitres are used to express quantities such as liquid medications, chemical solutions, beverage volumes, and lab samples. They are preferred for small to moderate liquid measurements where precision matters but workable magnitudes are well below a litre.

Notation and standards: the millilitre is accepted for use with the International System of Units (SI) as a non-SI unit. The recommended symbol is mL (capital L to avoid confusion with the number 1), though ml is widely used in many publications and products.

Density note: a volume in millilitres is a measure of space, not mass. The mass corresponding to a given millilitre depends on the material’s density (for water, at 4 °C, 1 mL is approximately 1 g).

See also: litre, cubic centimetre, liter.