Light-Year Distance Converter for Astronomical D...
Convert between light-years, parsecs, astronomical units, and kilometers. Understand the scale of the universe and why we use light-years to describe cosmic dista...
What is a Light-Year?
A light-year (ly) is the distance light travels in one year: approximately 9.461×10¹⁵ meters or 5.879×10¹² miles. It is the standard unit for interstellar distances. The nearest star (Proxima Centauri) is 4.24 ly; the Andromeda galaxy is 2.537 million ly; the observable universe is ~46.5 billion ly in radius.
🌌 Light-Year Distance Converter
Free calculator for instant results.
📐 Formula
1 ly = 9.461 × 10¹⁵ m
1 ly = 9.461×10¹² km = 63,241 AU = 0.3066 parsecs. 1 parsec = 3.086×10¹⁶ m = 3.26 ly. 1 AU = 1.496×10¹¹ m.
📝 Worked Example
Andromeda galaxy: 2.537 million ly
In parsecs: 2,537,000/3.26 = 777,816 parsecs = 0.778 Mpc
In km: 2.537×10⁶ × 9.461×10¹² = 2.4×10¹⁹ km
📝 How to Use
❓ FAQ
Why not just use kilometers for space distances?
Interstellar distances are so large that even light-years are difficult to visualize. Proxima Centauri in km: 40.2 trillion km. Light-years make these manageable numbers.
What is a parsec?
A parsec = distance at which 1 AU subtends an angle of 1 arcsecond. Used in professional astronomy. 1 pc = 3.26 ly. Kiloparsecs (kpc) and megaparsecs (Mpc) for galaxies.
Veer Kumavat
Founder & AuthorVeer is a 14-year-old student from Nashik, Maharashtra, who built SciFi Calculators to help students worldwide master STEM subjects. He is passionate about making complex science and math problems accessible through intuitive digital tools.