Voltage Ratio

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

  • Volts
  • Volts
  • dB

A change in voltage, from V1 to V2 can be expressed as a ratio in decibels with the equation RV = 20*log(V2 / V1). A doubling in the voltage level translates to a power ratio of 6 dB. Similarly, halving the power equals a -6 dB voltage ratio. This calculator can also be used to express differences between two distances or pressures.

  • dB = 20 log (V2/V1)