Light Travel Time Calculator
How long light takes to cross a distance.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Travel time
- 8.32 minutes
- Distance in km
- 1.4960e+8
- In light years
- 1.5812e-5
- In AU
- 1
Quick answer
Light travels 299,792 kilometres every second in a vacuum.
Time = distance ÷ c
How to use the Light Travel Time Calculator
- 1Enter the distance value.
- 2Choose the distance unit.
- 3Read light travel time and conversions.
Frequently asked questions
How far is one light year?
About 9.46 trillion kilometres.
How long is light from the Sun?
8 minutes 20 seconds.