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Astronomical Units to Kilometers Converter.

Convert astronomical units to kilometers using the exact IAU astronomical unit.

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Kilometers (km): 149,597,870.7

Kilometers (km)

0.0000000000

The astronomical unit is exactly 149,597,870.7 km.

FAQs

How does the astronomical units to kilometers converter work?

The astronomical unit is exactly 149597870.7 km.

Use Cases

Astronomy Education

Helps students and teachers quickly convert distances in the solar system from AU to kilometers for homework, projects, or classroom demonstrations.

Example: Convert 1.5 AU (Mars' distance) to km: 1.5 × 149,597,870.7 = 224,396,806.05 km.

Space Mission Planning

Assists amateur astronomers and space enthusiasts in visualizing distances to planets, asteroids, or spacecraft in more familiar units.

Example: Convert 5.2 AU (Jupiter's distance) to km: 5.2 × 149,597,870.7 = 777,908,927.64 km.

Frequently Asked Questions

What is an astronomical unit (AU)?
An astronomical unit is the average distance between Earth and the Sun, defined as exactly 149,597,870.7 kilometers by the International Astronomical Union in 2012.
How do I convert AU to kilometers?
Simply enter the number of astronomical units into the converter. The calculator multiplies your input by the exact IAU 2012 value of 149,597,870.7 km to give you the equivalent distance in kilometers.
Why use the IAU 2012 value?
The IAU 2012 definition is the internationally accepted standard, ensuring consistency in astronomical calculations. It replaced older, less precise estimates.

Tips & Common Mistakes

Tips

  • Remember that 1 AU is exactly 149,597,870.7 km, so you can also do the conversion manually by multiplying your AU value by this number.
  • For very large distances, consider using scientific notation to avoid errors when entering many zeros.
  • Double-check your input: a small mistake in the number of AU can lead to a large error in kilometers.
  • Use this converter for quick estimates, but for precise scientific work, always refer to the latest IAU definitions.

Common Mistakes to Avoid

  • Using an outdated value for the astronomical unit, such as 149,600,000 km, which can cause significant errors in calculations.
  • Confusing astronomical units with light-years or parsecs, which are different units of distance.
  • Forgetting to multiply by the exact value when doing manual conversions, leading to rounding errors.

Last updated: August 13, 2026