A milliliter (mL) is a unit of volume in the metric system of measurement. It is based on the liter (L), and uses the the prefix "milli-", which is one of a set of prefixes used in the International System of Units (SI), to indicate that it is L.

Milliliters and other units of volume

Although a liter is not an accepted SI unit, it is accepted for use with SI. The SI base unit of volume is the cubic meter (m3). A related unit, the cubic centimeter (cm3), is exactly equivalent to a milliliter, so the two can be used interchangeably. Cubic centimeters can also be abbreviated as cc. This abbreviation is still used today, particularly when referencing medical dosages, though it was originally used as part of the centimeter-gram-second system of units.

Below are some equivalences between milliliters and other measurements of volume in various systems of measurement:

1 mL  =  1 cm3
1,000 mL  =  1 L
1,000,000 mL  =  1 m3
3,784.4 mL  =  1 gallon
240 mL  =  1 cup