Enter the sound level and distance at point 1, and the sound level at point 2 into the calculator to find the distance at point 2.

Decibel Distance Formula

The following formula is used to calculate the decibel distance.

D2 = D1 / Sqrt (I2 / I1) 
  • Where D2 is the distance at point 2
  • D1 is the distance at point 1
  • I2 is the decibel level at point 2
  • I1 is the decibel level at point 1

To calculate distance from decibels, divide the distance at point 1 by the square root of the result of the decibels at point 2 over the decibels at point 1.

Decibel Distance Definition

What is decibel distance? A decibel distance is a measure of distance that a certain decibel level is reached given an initial distance and sound level from the sound source.

Example Problem

How to calculate decibel distance?

  1. First, determine the sound level at point 1.

    The sound level at point 1 in this example is found to be 20 dB.

  2. Next, determine the distance from the source at point 1.

    The distance from the sound source to point 1 is found to be 20 ft.

  3. Next, determine the sound level at point 2.

    The sound level at point 2 is found to be 3 dB.

  4. Finally, calculate the distance to point 2 from the source.

    The final distance is calculated to be 20 / Sqrt (3/20) = 51.639 ft.

About Decibel Distance

How does sound change with distance? The sound level from a source changes with the square of the change in distance.

decibel distance calculator
decibel distance formula