Convert light years to other units or calculate travel time at high speeds.
Distance Parameters
ly
%c
Conversion Results
Enter distance to convert
About this calculator
Quick Reference
1 ly9,460,730,472,580 km
1 ly63,241 AU
Nearest Star4.25 ly
Galaxy Width~100,000 ly
Overview
A light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). It is approximately 9.46 trillion kilometers. Despite the name, it is a unit of length, not time.
💡
Pro Tips
1 light-year ≈ 9.461 x 10¹² km.
1 light-year ≈ 63,241 Astronomical Units (AU).
The nearest star (Proxima Centauri) is about 4.25 light-years away.
!
Fun Facts
"Wait, did you know that when you look at stars, you are literally looking back in time? The light from the North Star (Polaris) left the star about 430 years ago!"
"If you could travel at the speed of light, it would still take you 100,000 years to cross our Milky Way galaxy."
"Voyager 1, the farthest man-made object, has traveled only about 21 light-hours in over 45 years."
