Light Year Converter
Convert a distance between light-years, astronomical units, parsecs, kilometres, miles and metres. Enter a value, pick the from and to units, and read the result.
How to convert astronomical distances
- Enter the distance value you want to convert.
- Choose the unit you are converting from.
- Choose the unit you are converting to and read the result.
Examples
Light-year to kilometres
1 light-year
9.4607e12 km
Parsec to light-years
1 parsec
3.2616 light-years
Frequently asked questions
How many kilometres are in a light-year?
About 9.4607 x 10^12 km, the distance light travels in one year in a vacuum. That is roughly 9.46 trillion kilometres.
What is a parsec?
A parsec is about 3.0857 x 10^13 km, or roughly 3.2616 light-years. It is the distance at which one astronomical unit subtends one arcsecond.
What is an astronomical unit (AU)?
One AU is about 1.496 x 10^8 km, the mean distance between Earth and the Sun. It is handy for measuring distances inside the Solar System.
Which units does this converter support?
Light-years, astronomical units, parsecs, kilometres, miles and metres. You can convert between any pair in either direction.
Are the conversions exact?
They use standard accepted factors and route through kilometres, so round-trip conversions return the original value to high precision.
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