How many millimeters are in one liter?

One liter has the volume of approximately one million cubic millimeters. Cubic millimeters are an expression of volume, and one liter of water at standard pressure and maximum density generally occupies this volume amount.

The variation of this conversion comes from factors such as impure water and irregularities in density, temperature and pressure. Until 1964, the standard metric units of fluid measurement, volume and mass were equivalent: one liter of water weighed one kilogram and occupied the volume of one cubic decimeter. The variations listed above led to the abandonment of these units in favor of more rigorously standardized units as determined by the International System of Units (SI).