Light Travel Time Calculator

How long would a light beam (or radio signal) take to reach a destination? Uses speed of light and typical distances (approximate).

Pick where your signal is going.
Round trip = “ping” time.
Sunlight reaches Earth in about 8 minutes.
We use c ≈ 299,792 km/s.
How we calculate

Time = distance ÷ c. For round trip, we multiply by 2. For Alpha Centauri we use light-years converted to seconds.