Light Travel Time Calculator
Find out how long light takes to travel any astronomical distance in AU, light-years, or parsecs. Click any reference object to use its distance.
Reference Distances (click to use)
Earth to Sun1 AU
Earth to Moon~1.26 light-seconds
Proxima Centauri4.244 ly
Sirius8.6 ly
Galactic Center~25,000 ly
Andromeda Galaxy~2.537 Mly