Astronomy & Space

Light-Year Converter

One light-year is the distance light travels in one year — about 9.461 trillion kilometers. This converter translates between light-years, kilometers, astronomical units (AU), and parsecs so you can make sense of cosmic distances.

Enter a Distance

Conversion Results

Light-Years

Kilometers

Miles

Astronomical Units

Parsecs

Light Travel Time

Famous Distances

Proxima Centauri (nearest star)

4.24 light-years = 40.1 trillion km

Sirius (brightest star)

8.6 light-years = 81.4 trillion km

Milky Way diameter

~100,000 light-years

Andromeda Galaxy

2.537 million light-years

Observable Universe radius

~46.5 billion light-years