Volt V RMS to dBm Calculator

Use this calculator to convert from Volt RMS to Power in dBm.

RMS means root-mean-square value or VRMS

The default impedance is 50 ohm. It can be changed to any value.

Formula

PdBm = 10*log10((VRMS)2 /Z) + 30

Example Calculation

For VRMS = 1 Volt and impedance (Z) = 50 ohm, the power is 13 dBm.

If instead you would like to convert from Vpeak-peak to dBm, use this calculator instead.

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