How to use the light-year calculator
Convert light-years to kilometres, AU and parsecs. Enter distance in the field above; the distance are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “how far is a light year”, “stars distance”, “ly to km”, “calculate light-year”, “find distance”.
Formula
Variables
- ly — Distance (light-years)
Worked example
With distance = 4.37 light-years, the calculator gives distance ≈ 41,343.39 trillion km; distance ≈ 276,363.5 AU; distance ≈ 1.33985 parsecs.
Frequently asked questions
What is the light-year calculator used for?
Convert light-years to kilometres, AU and parsecs. It helps with questions such as “how far is a light year”, “stars distance”, “ly to km”.
What is the formula for the light-year calculation?
Distance (trillion km) = ly × LY / 1e12. Distance (AU) = ly × LY / AU. Distance (parsecs) = ly / 3.26156. Here ly is distance (light-years).
What inputs do I need for the light-year converter calculator?
You need distance in light-years. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the light-year calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the light-year result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.