đŸŒŒ Astronomical Unit Calculator
Explore distances in the solar system by converting astronomical units into familiar measurements.
One astronomical unit (AU) equals the average distance between Earth and the Sun. Use this calculator to translate AU into kilometers, miles, or the time light needs to travel the same distance.
Enter a non-negative distance. Decimals are welcome for precision.
Astronomical Units (AU)
1
Kilometers (km)
149,597,871
Miles (mi)
92,955,807.27
Light Minutes
8.316746
Light Seconds
499.0048
Did you know? Neptune orbits the Sun at roughly 30 AU, which equals about 4.5 billion kilometers. Use the calculator to explore other solar system distances.
How to Use This Calculator
Select the starting unit
Pick whether your distance is expressed in AU, kilometers, miles, light minutes, or light seconds.
Enter the distance value
Input the numeric value you want to convert. The calculator handles decimals for precise astronomical measurements.
Review the conversions
See the equivalent distance across all supported units, including the time light takes to travel that distance.
Formula
1 AU = 149,597,870.7 km
1 AU = 92,955,807.3 miles
1 AU = 8.316746 light minutes
Converted Value = Input Ă— (Conversion factor to kilometers) Ă· (Conversion factor from target to kilometers)
Use the formula breakdown to confirm the calculation logic or perform the conversion manually if needed.
Full Description
The astronomical unit helps astronomers, educators, and space enthusiasts communicate vast solar-system distances in a manageable way. Because it approximates the average Earth–Sun separation, it provides intuitive context for planetary orbits, spacecraft trajectories, and comet paths.
This calculator transforms AU values into kilometers, miles, and light travel times so you can translate scientific figures into everyday language. When presenting to a general audience or collaborating with engineers, being able to express 5.2 AU as about 778 million kilometers (Jupiter's orbital distance) keeps discussions grounded.
The tool also supports reverse conversions, letting you start from kilometers or light seconds. That makes it easy to validate data from mission reports, textbooks, or observational logs.
Frequently Asked Questions
What exactly is an astronomical unit?
An astronomical unit (AU) is defined as 149,597,870.7 kilometers—the average distance from Earth to the Sun. It is a standard unit for expressing distances within the solar system.
Why convert AU to other units?
AU is convenient in astronomy but may feel abstract. Converting to kilometers, miles, or light travel time helps communicate distances to broader audiences and compare them with engineering specifications.
How precise are the conversion factors?
The calculator uses the IAU 2012 definition of the astronomical unit and internationally recognised constants for speed of light and mile-to-kilometer conversions, ensuring scientific accuracy.
Can I use this for interstellar distances?
You can, but the values will become very large. For distances beyond our solar system, consider using light years or parsecs, which are specifically designed for those scales.