Light-Years Converter: Astronomy Distances in Kilometres
A light-year is a distance, not a time: how far light travels in one year. That distance is enormous, so conversions need trillions.
What is the Light Years Converter?
Enter a distance and pick a direction. One light-year is about 9.461 trillion kilometres, and the tool multiplies or divides by that figure. It is an astronomy unit conversion, not a travel-time estimate.
How to use it
- Enter a distance.
- Pick the conversion direction.
- Click Convert Distance.
Worked example
One light-year is about 9,461,000,000,000 kilometres, or about 5,879,000,000,000 miles.
How many kilometres is one light-year?
About 9.461 trillion kilometres.
Frequently asked questions
Is a light-year a unit of time?
No. It is the distance light travels in one year in a vacuum.
Why are the numbers so large?
Light moves at about 300,000 km per second, so a year of travel covers trillions of kilometres.