The decimetre (SI symbol dm) is a unit of length in the metric system, equal to one tenth of a metre (the International System of Units base unit of length), ten centimetres or 1/0.254 (approximately 3.93700787) inches.

The c is pronounced /s/, unlike in decametre. The common non-SI metric unit of volume, the litre, is defined as one cubic decimetre (however, from 1901 to 1964, there was a slight difference between the two due to the litre being defined with respect to the kilogram rather than the metre).

See also