Lightning Distance Calculator

Calculate the distance to a lightning strike based on the time delay between seeing the lightning and hearing the thunder.

Input Parameters

Calculation Results

Calculation Formula

Distance (km) = Time Delay (seconds) × 0.343

Where:
Time Delay: The time difference between seeing the lightning and hearing the thunder.
0.343: The speed of sound in km/s (approx. 343 meters per second).

Distance to Lightning

-- km

Lightning Distance Calculator Usage Guide

Learn how to use the Lightning Distance Calculator and its working principles.

How to Use the Calculator

  1. Observe a lightning strike and start counting the seconds until you hear the thunder.
  2. Enter the time delay (in seconds) into the input field.
  3. Click the "Calculate" button to determine the distance to the lightning strike.
  4. The result will be displayed in kilometers.

Working Principle

The speed of sound in air is approximately 343 meters per second (or 0.343 kilometers per second). When lightning strikes, you see the flash almost instantly because light travels much faster than sound. The thunder follows the lightning strike later, and by measuring the time delay between seeing the lightning and hearing the thunder, you can calculate the distance to the lightning.

Example: If you count 5 seconds between seeing the lightning and hearing the thunder, the lightning is approximately 5 × 0.343 = 1.715 kilometers away.

Safety Note

Use this calculator for educational purposes. If you hear thunder, you are close enough to be struck by lightning. Seek shelter immediately if you detect any risk.