Convert length and distance units — meters, feet, inches, kilometers, miles, light years and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 au | 149600 km | |
| 0.01 au | 1.496e+06 km | |
| 0.1 au | 1.496e+07 km | |
| 1 au | 1.496e+08 km | |
| 5 au | 7.48e+08 km | |
| 10 au | 1.496e+09 km | |
| 50 au | 7.48e+09 km | |
| 100 au | 1.496e+10 km | |
| 1000 au | 1.496e+11 km |
Multiply the number of Astronomical Units by 149600000 to get Kilometers. Formula: km = au × 149600000. Example: 10 au × 149600000 = 1496000000 km. To reverse, divide Kilometers by 149600000 to get Astronomical Units.
| Astronomical Unit (au) | Kilometer (km) |
|---|---|
| 0.001 au | 149600 km |
| 0.01 au | 1496000 km |
| 0.1 au | 14960000 km |
| 0.5 au | 74800000 km |
| 1 au | 149600000 km |
| 2 au | 299200000 km |
| 5 au | 748000000 km |
| 10 au | 1496000000 km |
| 20 au | 2992000000 km |
| 50 au | 7480000000 km |
| 100 au | 14960000000 km |
| 250 au | 37400000000 km |
| 500 au | 74800000000 km |
| 1000 au | 149600000000 km |
| 10000 au | 1.496×1012 km |
To convert Astronomical Unit to Kilometer, multiply by 149600000. Example: 10 au = 1496000000 km
To convert Kilometer back to Astronomical Unit, divide by 149600000 (multiply by 6.6845×10-9). Use the swap button above.
Start with 100 Astronomical Units = 14960000000 km as your reference point. Scale up or down from there.
NASA and ESA mission planners express spacecraft distances in AU for scientific communication, then convert to kilometers for precise orbital mechanics calculations, thruster burn timing, and deep-space navigation commands.
Planetary scientists describe planet orbital distances in AU (Mars: 1.52 AU), then convert to kilometers (227.9 million km) for calculating signal delays, fuel requirements, and mission windows.
Near-Earth object trackers report asteroid distances in AU for public communication, then convert to kilometers for impact probability calculations and trajectory modelling by planetary defence teams.
Astronomy teachers use AU-to-km conversions to make solar system distances tangible — "Jupiter is 5.2 AU, which is 778 million km from the Sun — that's 778 million 1-kilometre segments laid end to end."
Engineers operating the James Webb Space Telescope work in AU for orbital planning around the L2 point, converting to kilometers for precise station-keeping manoeuvre calculations.
Amateur astronomers planning observations convert AU-based ephemeris data to kilometers to estimate apparent sizes of planets, angular diameters, and light travel times to solar system objects.
The Astronomical Unit is a unit of Length measurement (symbol: au). 1 au = 149600000 km. Used in scientific and practical Length measurement applications.
The Kilometer is a unit of Length measurement (symbol: km). It is part of an internationally recognised measurement system used alongside the Astronomical Unit.
The astronomical unit has ancient roots — Aristarchus of Samos attempted to measure the Earth-Sun distance around 270 BC, estimating it at 18–20 lunar distances (the true value is about 390). For centuries the AU was estimated using Venus transit observations and trigonometry. Edmond Halley organised the first coordinated international transit-of-Venus expedition in 1716. The modern value was determined by radar ranging to Venus in 1961. The IAU formally defined the AU as exactly 149,597,870,700 metres in 2012 — a fixed constant of physics, not a measured distance.
The kilometre was introduced in 1795 as part of the French metric system — exactly 1,000 metres. France was the first country to adopt a universal decimal measurement system, replacing a chaotic patchwork of regional units. The metre itself was defined as one ten-millionth of the distance from the North Pole to the equator through Paris. By the 20th century, the kilometre had become the world's standard unit for road distances, replacing miles in country after country. The US remains the only major exception, still officially using miles for road distances.
Common use: Astronomical Unit to Kilometer conversion is needed when working with international standards, scientific publications, or reference materials that use different unit systems for Length measurement.