Reference Designer Calculators

dBm to Volts

RF Engineers often express the power in dBm. The formula gives voltage value corresponding to a power value in dBm and Vice Versa.

Following is the formula for dBm to RMS voltage conversion.

P(dBm) = 10 log10(v2/(R*p0))

Where p0 is the reference wattage and is 1mW or 1x10-3 watts.

R is the load impedance, and is typically 50 Ohms for RF systems.

To Calculate dBm from voltageenter the value in V(voltage) and hit P(dBm) button.

To Calculate voltage from dBm enter the value in P(dBms) and hit V(voltage) button.

Res Resistance in ohms
  (Voltage in volts) :
  (Power in dBm)

We strongly suggest that you go through the following video to understand the relationship of dBm and volts.