Calculate Lightning and Thunder

Stopwatch and calculator for calculating how far away lightning is from you from the time between lightning and thunder. The sound travels about 343 meters in one second, about 20 kilometers in one minute.



Time between lightning and thunder: seconds
Distance of the lightning: kilometers

The calculator can also be used without the stopwatch, simply enter one of the two values and press Calculate. The distance of a noise is measured, which does not have to be thunder, but can be anything that can be heard over a long distance and which noise source can be seen.

You are safe from lightning in buildings with lightning rods and in closed cars. In an open field you should squat down and make yourself as small as possible, but not lie down. Avoid rock faces, trees, etc.

Physics commonly uses SI units. Here is a calculator to convert units.