This calculator determines the distance to a lightning strike based on the time delay between seeing the lightning and hearing the thunder.
Learn how to use the Lightning Distance Calculator and its working principles
The speed of light is so fast that it reaches us almost instantaneously, while the speed of sound is much slower (approximately 343 meters per second or 0.343 kilometers per second at sea level). By measuring the time delay between seeing the lightning and hearing the thunder, we can calculate the distance to the lightning strike using the formula:
Distance (km) = Time Delay (seconds) × 0.343
If you can hear thunder, you are close enough to be struck by lightning. It is important to seek shelter immediately if you detect any signs of an approaching storm.