Light-Year Converter
Convert cosmic distances between light-years, km, AU, and parsecs.
Distances across the cosmos
Astronomical distances are so vast they need their own units: light-years, parsecs, and astronomical units. This converter translates between them and everyday kilometres and miles.
One light-year is about 63,241 astronomical units or 0.307 parsecs. Enter a distance in any unit to grasp its scale in the others.
Cosmic and private
The conversion runs in your browser, so nothing you enter is uploaded.
Frequently Asked Questions
What is a light-year?
The distance light travels in one year — about 9.46 trillion kilometres. It is a unit of distance, not time.
What is a parsec?
About 3.26 light-years, a distance unit used by astronomers based on parallax.
What is an AU?
An astronomical unit, the average Earth-Sun distance, about 150 million kilometres.
Browse the full set of free, private, in-browser tools.