Kilometer to Astronomical Unit Converter

About this conversion

The kilometer (km) is a unit of length in the metric (SI), commonly used for road and highway distances and geographic measurements. The astronomical unit (au) belongs to the astronomical and is typically found in measurements related to distances between planets and orbital radius of planets. By definition, one kilometer is one thousand meters. One astronomical unit is approximately 149,597,870.7 km — the mean distance from Earth to the Sun. The conversion factor between these two units is 6.684587122268446e-9: multiplying any value in km by this number gives the equivalent in au. For example, 10 km equals 0.0000 au. Going the other direction, 1 au equals 149597870.7 km. Adopted alongside the metric system, the kilometer became the standard unit for land distance in most countries by the 20th century.