Voltage Ratio

dB Voltage Calculator

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

Volts
Volts
dB

What It Is

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.

Essential Formulas

  • dB = 20 log (V2/V1)

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