Enter the sound pressure and reference pressure into the calculator to determine the sound pressure level, also known as dB level.

Sound Pressure Level Formula

The following equation is used to calculate a sound pressure level.

dB = 10 * log ( p^2 / pr^2) 
  • Where dB is the sound pressure in decibels
  • P is the sound pressure (pascals)
  • pr is the reference pressure (pascals)

To calculate the sound pressure level, divide the sound pressure squared by the reference pressure squared, take the log of this result, then multiply by 10.

Sound Pressure Level Definition

A sound pressure level is the pressure differential caused by the pressure of a sound wave and an ambient pressure.

Sound Pressure Example

How to calculate a sound pressure?

  1. First, determine the sound pressure.

    Measure the total pressure of the sound.

  2. Next, determine the reference pressure.

    Most often this is just the atmospheric pressure.

  3. Finally, calculate the sound pressure level.

    Calculate the decibels of the sound using the equation above.


What is a sound pressure level?

A sound pressure level is a pressure wave caused by a differential in pressure produces by sound waves.

sound pressure level calculator
sound pressure level formula