Conversions

Instant, private, and free

Astronomical Unit Converter.

Convert astronomical units to common distance units.

On-device calculationNo signup
01

Set your values

Results update as you type.

Result: 149,597,870.7

Result

0.00000000

Use Cases

Astronomy Education

Helps students and educators quickly convert distances between Earth and other celestial bodies into familiar units like kilometers or miles.

Example: Convert 1 AU to miles to understand Earth-Sun distance in miles.

Space Mission Planning

Assists engineers and scientists in converting mission distances from AU to kilometers or miles for navigation and communication calculations.

Example: Convert 2.5 AU (Mars distance) to kilometers for trajectory analysis.

Frequently Asked Questions

What is an astronomical unit (AU)?
An astronomical unit (AU) is the average distance between Earth and the Sun, approximately 149.6 million kilometers or 92.96 million miles. It is used to measure distances within our solar system.
How do I convert AU to kilometers?
To convert AU to kilometers, multiply the number of AU by 149,597,870.7 (the exact value). For example, 5 AU is about 747,989,353.5 km. This converter does the calculation for you.
Can I convert kilometers to AU with this calculator?
Yes, you can select 'KM' as the 'Convert from' unit and 'AU' as the 'Convert to' unit. The calculator will divide the kilometers by 149,597,870.7 to give you the equivalent in AU.

Tips & Common Mistakes

Tips

  • Remember that 1 AU is approximately 149.6 million kilometers or 92.96 million miles.
  • For quick mental estimates, you can round 1 AU to 150 million km or 93 million miles.
  • Use the converter for any distance within the solar system; it's not suitable for interstellar distances.
  • Double-check your selected units before converting to avoid errors.

Common Mistakes to Avoid

  • Confusing AU with light-years; AU is for solar system distances, light-years for interstellar.
  • Forgetting to select the correct 'Convert from' and 'Convert to' units, leading to reversed conversions.
  • Using approximate values when exact conversions are needed; this calculator uses the precise definition.

Last updated: August 13, 2026