Decimeter (dm)

Metric (SI)Current unit

One tenth of a meter (10 cm). Rarely used in everyday practice.

1 decimeter = 0.1 meters (exactly).

About the decimeter

Deci, meaning a tenth, was among the prefixes of the first metric system, and Wikipedia's prefix table dates it to 1795. The decimeter (dm) is therefore 10 centimeters, 100 millimeters or about 3.937 inches. Of all the early metric multiples it is the one that shows up least in daily speech, since people reach for centimeters or meters instead.

Its real importance is as the edge of the liter. A liter is defined as one cubic decimeter, so a 10 cm cube holds exactly one liter. Between 1901 and 1964 the liter was defined through the kilogram instead, which made it very slightly different from the cubic decimeter. The unit also survives in a few specialist places. Chemists record the path length used for specific rotation in decimeters, and ship draught marks are given in decimeters in most of the world. A standard compact disc, at 120 mm, is 1.2 dm across.

Sources: Wikipedia: Decimetre; Wikipedia: Metric prefix; NIST: metric (SI) prefixes

Decimeter conversion chart

1 decimeter expressed in every other length unit:

More Metric (SI) units

• meter (length)
• kilometer (length)
• centimeter (length)
• millimeter (length)
• micrometer (length)
• nanometer (length)
• picometer (length)
• hectometer (length)
• decameter (length)
• kilogram (weight & mass)
• gram (weight & mass)
• milligram (weight & mass)
• microgram (weight & mass)
• metric ton (weight & mass)
• quintal (weight & mass)
• carat (weight & mass)

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