dB to Ratio Conversion Calculator

This tool converts a Power Gain in dB to the ratio of:

  • Power (Pout/Pin)
  • Voltage (Vout/Vin)


PdB = 10*Log10(P1/P2)

PdB = 20*Log10(V1/V2)

and therefore the ratios

P1/P2 = 10(PdB/10)

V1/V2 = 10(PdB/20)

Example Calculations

A 10 dB value gives a power ratio of 10 and a voltage ratio of 3.162.

A -10 dB value gives a power ratio of 0.1 and a voltage ratio of 0.3162.

Note that negative dB values have a higher voltage ratio value than power ratio. The reverse is true for positive dB values.


Converting dB to a ratio involves using exponentiation based on whether you are dealing with power ratios (using 10dB/10​) or voltage/current ratios (using 10dB/20​).

This reverse conversion from logarithmic dB values to linear ratios is crucial for understanding the actual magnitudes in practical applications across various fields like audio engineering, electronics, and telecommunications.