How many kilometers are in 1 AU?

One AU equals approximately 149,597,870.7 km (about 149.6 million km). The IAU fixed this value exactly at 149,597,870,700 meters in 2012.

How do I convert AU to kilometers?

Multiply the AU value by 149,597,870.7. For example, Mars at 1.52 AU is 1.52 x 149,597,870.7 = about 227.4 million km from the Sun.

Why do astronomers use AU instead of kilometers?

AU gives cleaner numbers for solar system distances. Saying Mars is at 1.52 AU is more intuitive than 227 million km. AU also makes orbital calculations simpler because many formulas use AU as the natural distance unit.

Astronomical Units to Kilometers (au to km) Converter

1 au = 149,597,870.7 km

1 Astronomical Unit equals 149,597,870.7 Kilometers (1 au = 149,597,870.7 km). Convert Astronomical Units to Kilometers with formula, table, and examples.

One astronomical unit equals approximately 149,597,870.7 kilometers, or roughly 149.6 million km. This is the most commonly used AU conversion, as kilometers are the standard metric unit for geographic and planetary distances. The AU-to-km conversion appears in every astronomy textbook and space mission report.

How to Convert Astronomical Units to Kilometers

km = au × 149,597,870.6999999881

Multiply the value in Astronomical Units by 149,597,870.6999999881

Take your value in Astronomical Units
Multiply by 149,597,870.6999999881
Read the result in Kilometers

Common Astronomical Units to Kilometers Conversions

Astronomical Units (au)	Kilometers (km)	Status
0.00001 au	1,495.9787 km
0.0001 au	14,959.7871 km
0.001 au	149,597.8707 km
0.01 au	1,495,978.707 km
0.1 au	14,959,787.07 km
0.39 au	58,343,169.573 km
0.72 au	107,710,466.904 km
1 au	149,597,870.7 km
1.52 au	227,388,763.464 km
5.2 au	777,908,927.64 km
9.5 au	1,421,179,771.65 km
19.2 au	2,872,279,117.44 km
30 au	4,487,936,121 km
39.5 au	5,909,115,892.65 km

Good to Know About Astronomical Units to Kilometers Conversion

The AU-to-km conversion is the bread and butter of popular astronomy. Every planetarium show, science documentary, and NASA press release uses it. When people ask 'how far is Mars?', the answer comes in both AU and millions of km.

Astronomical Units to Kilometers: What You Need to Know

The Earth orbits the Sun at 1 AU (149.6 million km). Mars at opposition is about 0.37 AU (55.7 million km) from Earth. Jupiter orbits at 5.20 AU (778 million km). The Voyager 1 spacecraft, over 160 AU from the Sun, is about 24 billion km away. This conversion is essential for understanding solar system distances.

What is a Astronomical Unit? au

Exactly 149,597,870,700 meters by IAU 2012 definition. Roughly the average distance from the Earth to the Sun. Used for distances within our solar system.

Astronomical solar system distances astronomy planetary science

Learn more about Astronomical Unit →

What is a Kilometer? km

A metric unit of length equal to 1000 meters. The standard unit for measuring road distances and geographic distances in most countries.

Metric road distances geography running

Learn more about Kilometer →

Going the other way? Use our Kilometers to Astronomical Units converter.

Astronomical Units to Kilometers FAQ

One AU equals approximately 149,597,870.7 km (about 149.6 million km). The IAU fixed this value exactly at 149,597,870,700 meters in 2012.
Multiply the AU value by 149,597,870.7. For example, Mars at 1.52 AU is 1.52 x 149,597,870.7 = about 227.4 million km from the Sun.
AU gives cleaner numbers for solar system distances. Saying Mars is at 1.52 AU is more intuitive than 227 million km. AU also makes orbital calculations simpler because many formulas use AU as the natural distance unit.

Non-Frequently Asked Questions About Astronomical Units to Kilometers

Questions nobody should ask - but someone did.

At 100 km/h non-stop, it would take about 170 years to drive 1 AU (149.6 million km). You would need roughly 150,000 oil changes. Your warranty would definitely be void.