Astronomical Units to Kilometers
Convert AU to km quickly with this free online calculator. The page explains the conversion rule, gives practical examples and provides a quick reference table.
One astronomical unit is 149,597,870.7 kilometers.
How to use the Astronomical Units to Kilometers
- Enter the number you want to convert.
- Confirm the source unit shown beside the input.
- Choose decimal precision if you need more or less detail.
- Read the converted result.
- Copy the result when you need to use it elsewhere.
How the conversion works
One astronomical unit is 149,597,870.7 kilometers.
For a simple fixed-factor conversion, the calculator multiplies the entered value by the stated factor. Temperature scales and certain specialized tools use their specific mathematical relationship instead.
Common AU to km conversions
| AU | km |
|---|---|
| 1 AU | 149,597,870.7 km |
| 2 AU | 299,195,741.4 km |
| 5 AU | 747,989,353.5 km |
| 10 AU | 1.49598e+09 km |
| 20 AU | 2.99196e+09 km |
| 50 AU | 7.47989e+09 km |
Example
For example, entering 1 AU gives approximately 149,597,870.7 km using the rule above. Change the input to test your own value.
Frequently asked questions
Accuracy note: This calculator is a practical reference. For regulated, safety-critical or specialized work, verify the result against the applicable standard.
Page reviewed: August 24, 2026.