The decimeter is a metric unit of length. One decimeter equals 0.1 meters, so every conversion on this page starts from that single number. Metric units are built from the meter with a prefix, so moving between them only ever means shifting the decimal point.

Because the whole system works in powers of ten, you can convert decimeters to any other metric unit without memorizing odd numbers. The table further down does the arithmetic for the values people look up most.

In writing, the decimeter is usually shortened to "dm". One decimeter is 0.1 meters, and that ratio is what every figure on this page is built from.