Light Year Converter

What Is a Light Year?

A light year is a unit of distance, not time. It measures how far light travels in one year through space. Because light speed is constant, astronomers use light years to describe vast cosmic distances in a practical way.

One light year equals approximately:

• 9.461 trillion kilometers
• 5.879 trillion miles
• 63,241 astronomical units (AU)

Light Year Conversion Formulas

$$Kilometers = Light\ Years \times 9.4607 \times 10^{12}$$

$$Miles = Light\ Years \times 5.8786 \times 10^{12}$$

$$Astronomical\ Units = \frac{Light\ Years}{1.5813 \times 10^{-5}}$$

Real-World Examples

• Proxima Centauri is about 4.24 light years from Earth.
• 1 light year is about 63241 AU.
• 1 parsec equals about 3.26 light years.

Related Converters

For more astronomy distance conversions, try the Astronomical Unit Converter or the general Length Converter.