Kilometers to Decimeters (km to dm)

1 kilometer equals 10,000 decimeters exactly.

1 kilometer = 10,000 decimeters

How to convert kilometers to decimeters

To convert kilometers to decimeters, multiply the number of kilometers by 10,000. This factor is exact. To go the other way, multiply decimeters by 0.0001.

decimeters = kilometers × 10,000

Example: 10 kilometers = 100,000 decimeters.

About these units

Kilometer (km)

Metric (SI)Current unit

1,000 meters. The standard unit for road distances in most countries.

A name for 1,000 meters took a while to settle. In 1793 France's National Convention made the metre the sole French unit of length, and the first proposed name for the thousand-metre multiple was millaire. Everyday French usage then leaned on the myriametre, 10,000 meters, well into the 1800s. The Netherlands adopted the kilometre in 1817, under the local name mijl, and made it the only official unit of that size in 1867. In 1935 the CIPM dropped the myria- prefix, which left the kilometre as the standard unit for road-scale distances.

Kilo- is the SI prefix for a thousand, and the kilometre is now the preferred unit for land distances in most of the world, with the United States, the United Kingdom and Liberia among those that still use the mile. One kilometre is about 0.621 mile. The main span of Lisbon's 25 de Abril Bridge, at 1.013 km, gives a sense of the scale. Even its pronunciation has been argued over: in 1970 Australia's Metric Conversion Board made stress on the first syllable official, although Prime Minister Gough Whitlam argued for stress on the second. Military slang in several countries calls it a klick.

1 kilometer = 1,000 meters (exactly).

Sources: Wikipedia: Kilometre; Wikipedia: Metric prefix; BIPM: history of the metre

Decimeter (dm)

Metric (SI)Current unit

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

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.

1 decimeter = 0.1 meters (exactly).

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

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