Power Ratio

To determine the power ratio in dB from one wattage level to another, enter the values below, then press "Calculate".

  • Watts
  • Watts
  • dB

A change in power, from P1 to P2 can be expressed as a ratio in decibels with the equation dB = 10*log(P2/ P1) . A doubling in the power level translates to a power ratio of 3 dB. Similarly, halving the power equals a -3 dB power ratio.

  • dB = 10 log (P2/P1)