dB to Watt Calculator

This calculator is used to convert from dB to Watt as a measure of sound or noise power level.

Enter the power level in dB and the tool will provide the Watt equivalent.

🔁 Watt to dB

Formula

Sound power level in Watt is determined by the following formula:

Lw = LR * 10(LwdB/10)

where

  • LwdB is the sound power level in deciBel.
  • The reference power LR is one trillionth of a Watt or 10-12 W (which is the lowest level that can be discerned by the human ear)

Note: Sound power level is not the same as sound pressure level. However the units are the same (dB) and this calculator applies to both.

Example Calculation

A turbojet engine has a sound level of 170 dB. The calculator above can be used to find this is equivalent to 100,000 Watt.

Human breath of one person has a sound level of 10 dB. This is equivalent to 10-11 Watt.

Background

The picture below shows the sound power level in dB vs the sound power level in Watt (W)

Sound Power Level dB to Watt chart

Notes

  1. dB is also the unit for Sound Pressure Level (SPL) sensitivity specified as dB (1W/1m) and can be computed at any distance away from the audio source.
  2. SPL on Wikipedia
  3. dB is sometimes confused with dBm (dB referenced to 1 milliwatt). dBm is used in Radio Frequency systems as a unit of power. It can be converted directly to Watt.
  4. dB can be converted to a linear power ratio. For example the ratio between output and input power to an amplifier. This ratio is also called the gain.
  5. Use this calculator to add audio dB values together. Note that it’s not the same as adding general dB values.