1 AU in KM

Earth from space

1 AU in KM = 149,598,000 kilometers

An astronomical unit is a method that astronomers use to measure large distances in the Solar System. 1 astronomical unit, or 1 au, is the average distance from the Sun to the Earth.

The Earth’s orbit around the Sun is actually elliptical. It varies from 147 million km to 152 million km. So the measurement of an astronomical unit is just the Earth’s average distance from the Sun. That’s where the more precise measurement of 1 AU to KM (149,598,000 km) comes from.

Here are some other distances in the Solar System:
Mercury: 0.39 AU
Venus: 0.72 AU
Mars: 1.5 AU
Jupiter: 5.2 AU
Saturn: 9.6 AU
Uranus: 19.2 AU
Neptune: 30.1 AU
Pluto: 39.5 AU
Eris: 67.7 AU
Oort Cloud: 50,000 AU
Alpha Centauri: 275,000 AU

We have written many articles about large distances in space. Here’s an article that explains how far space is, and here’s an article about the distance to stars.

You can also check out this cool calculator that lets you convert astronomical units into any other distance.

We have also recorded an episode of Astronomy Cast detailing how astronomers measure distance in the Universe. Check out Episode 10: Measuring Distance in the Universe.