dBm to V/m Calculator

Use this calculator to convert Power in dBm to E-field strength in volt-per-meter (V/m).

The signal at the output connector of a transmitter is expressed in Volt or dBm. The field intensity at any distance away from the transmitter is expressed in terms of V/m.


  • Output power in either dBm or Watt
  • Antenna gain (dBi) and
  • Distance from the transmitter (meters)



???? V/m to dBm


Field Strength (V/m) = √(30*Pwatt*10(GaindBi/10))/Distance

Example Calculation

An output power level of 0 dBm with an antenna having gain of 3 dBi results in a field strength of 0.000244 V/m at a distance of 1000 meters.


Field strength, in the context of electromagnetic waves, refers to the intensity or magnitude of an electromagnetic field at a specific point in space. It is a measure of how strong the electric and magnetic fields are at a particular location, typically expressed in units like volts per meter (V/m) for electric field strength.

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