A cubic decimetre (symbol dm³) is an SI derived unit of volume. It is the volume of a cube of side length 1 decimetre (10 cm).

1 cubic decimetre is equal to 1 litre. See 1 E-3 m³ for a comparison with other volumes.

The old definition was the volume of 1 kilogram of pure water at 4 degrees celsius and 760 mm of mercury (or approximately 1.76 pints).