Reference Designer Calculators



dBm to milliWatts and milliwatts to dBm


RF Engineers often express the power in dBm in place of milliWatts or watts. The formula converts a power expressed in dBm to milliWatt ( and also milliwatts to dBm).

Following is the formula for dBm to Watt conversion.

P(dBm) = 10 log10(p/p0)

Where p0 is the reference volatge and is 1mW or 1x10-3 Watts. To Calculate dBm from wattage enter the value in P(milliwatts) and hit P(dBm) button.

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


  (Power in milliwatts) :
  (Power in dBm)