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Image & Data Auxiliary
Astronomical Unit Converter
Convert between light-years, parsecs, AU and kilometers.
Try the tool
1 ly equals:
- 1.0000e+0 light-years
- 3.0658e-1 parsecs
- 6.3242e+4 astronomical units
- 9.4610e+12 kilometers
Tool principle
Uses IAU 2012 constants: 1 AU = 149,597,870.7 km, 1 pc = 30.857 × 10¹² km, 1 ly = 9.461 × 10¹² km.
Data source: Native algorithm.
User guide
- 1Enter a value and pick its unit.
- 2All four equivalent values appear at once.
Frequently asked questions
Why do parsecs matter?＋
Astronomers use parsecs because they map directly to observed parallax angles.