Millimeter to Kilometer Converter

About this conversion

The millimeter (mm) is a unit of length in the metric (SI), commonly used for engineering and manufacturing tolerances and bolt and screw dimensions. The kilometer (km) belongs to the metric (SI) and is typically found in measurements related to road and highway distances and geographic measurements. By definition, one millimeter is one thousandth of a meter (0.001 m). One kilometer is one thousand meters. The conversion factor between these two units is 0.000001: multiplying any value in mm by this number gives the equivalent in km. For example, 10 mm equals 0.0000 km. Going the other direction, 1 km equals 1000000 mm. Adopted alongside the metric system, the kilometer became the standard unit for land distance in most countries by the 20th century.