Field Intensity Calculation

Field Intensity Calculation

Below is a calculation tool to help determining the actual field intensity or power density (in V/M) at a given distance with a known antenna gain.
This calculation tool will assist:
  • The calculation of field intensity levels required by certain immunity standards.
  • Calculating the required power amplifier and antenna combinations for new testing requirements.
  • For safety (radiation hazard) or electromagnetic interference (EMI) effects.


Power: Watts
Antenna Gain:
Distance: Meters



Field Strength Formula with Antenna Gain dBi

This calculation tool to help determining the required power to produce a desired field intensity using antenna gain and separation distance.

Desired V/M:
Antenna Gain:
Distance: Meters

Transmit Power Formula with Antenna Gain dBi

Field Intensity Calculation Microsoft Excel

Further Reading:

View our other RF Conversion formula sheets:
Useful formulas for RF related conversions
Magnetic field conversions
dBm to Volts to Watts conversion
VSWR Calculations