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dBm to RMS Voltage calculator

This tool converts dBm Power to RMS Voltage.

  • dBm = deciBel relative to one milliwatt
  • RMS = Root mean square

Calculator

Enter

  • dBm value
  • Impedance (default Z is 50 ohm, although you can change that to any value)

🔁 Convert VRMS to dBm

dBm to Voltage Formula

VRMS = SQRT(Z/1000)*10(PdBm/20)

Example Calculations

1 dBm into a 50 ohm impedance translates to Voltage of 251 millivolt.

The same power into half the impedance value gives 177 mV.

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