Parsec to Light-Year Converter Formula

Understand the math behind the parsec to light-year converter. Each variable explained with a worked example.

Use the Parsec to Light-Year Converter

Formulas Used

Light-Years

light_years = parsecs * 3.26156

Astronomical Units

au = parsecs * 206265

Kilometres

km = parsecs * 3.0857e13

Variables

VariableDescriptionDefault
parsecsDistance(pc)1

How It Works

Parsec Conversion

1 pc = 206 265 AU ≈ 3.2616 ly ≈ 3.0857 × 10¹³ km

Parsecs are the natural unit in stellar astronomy because they link directly to parallax measurement.

Worked Example

Sirius is about 2.64 parsecs away.

parsecs = 2.64
  1. 01ly = 2.64 × 3.26156 = 8.610 ly
  2. 02AU = 2.64 × 206265 = 544 539 AU
  3. 03km = 2.64 × 3.0857e13 ≈ 8.146e13 km

Ready to run the numbers?

Open Parsec to Light-Year Converter