What is the Light Year Converter?
Convert light-years to parsecs, astronomical units, kilometers, meters, and miles with this free light year converter. Enter any distance in any unit and get instant results across all astronomical scales, plus step-by-step conversion formulas. Runs entirely in your browser with no signup.
How to use the Light Year Converter
- Enter a distance value.
- Select the input unit: light-years, parsecs, AU, km, m, or miles.
- View instant conversions to every other unit.
- Use presets like 1 ly, 4.24 ly, or 1 parsec for quick examples.
- Copy the full conversion table and steps.
Common use cases
- Converting 4.24 light-years to kilometers
- Finding how many AU are in 1 parsec
- Translating astronomy textbook distances to miles
Frequently asked questions
- How many kilometers are in a light-year?
- One light-year equals about 9.461 × 10¹² kilometers — roughly 9.46 trillion km.
- How do you convert light-years to parsecs?
- Divide light-years by 3.2616, or multiply parsecs by 3.2616 to get light-years. One parsec is the distance at which 1 AU subtends 1 arcsecond of parallax.
- What is 1 AU in light-years?
- One astronomical unit (Earth–Sun distance) is about 1.581 × 10⁻⁵ light-years, or roughly 8.3 light-minutes.
- Can I convert miles to light-years?
- Yes. Enter the distance in miles and the tool converts to light-years, parsecs, AU, km, and meters automatically.
