Mutual conversion of decibel value and true value

VoltagePowerdB VoltagedB Power
dB Voltage
dB Power

About voltage/power/decibel mutual conversion

You can perform voltage/power/decibel voltage/decibel power unit conversion. Normal impedance values used are 50 ohm (radio), 75 ohm (TV), 600 ohm (audio). Please select the appropriate impedance value according to the application.


Generally, when “dBm” values are used, “dBmW” is displayed. This tool uses PD (terminal voltage) to perform the calculation. In the case of EMF (Open circuit voltage), use the conversion below.

Voltage: PD = EMF voltage / 2
dB: PD = EMF voltage – 6 dB

Corresponding dB value table