Received Field Intensity and Power Density Calculation

Below is a calculation tool to help determine the received field strength (in V/M or dBµV/m) and convert that result into power density (µW/m2, mW/m2, W/m2, or µW/cm2 ).
Field intensity or power density calculations are necessary when:
  • estimating electromagnetic interference (EMI) effects
  • determining potential radiation hazards (personnel safety and RF exposure)
  • measuring or verifying specifications


Received Signal:
: dB/m
Cable Loss: dB
Preamplifier Gain: dB

Field intensity
Power density


Convert dBm to dBuV formula
Gain dBi to Antenna Factor formula

Field intensity (dBµV/m) = RS(dBµV) + AF + CL - G dBuV/m to V/m formula
Volts per meter squared to Watts per meter squared formula
All conversions are based on:
* 50 ohm impedance
* Far-field measurement
* Free-space conditions (impedance of 377 ohm)


A handy little Field Intensity and Power Density Conversion TableAdobe Acrobat

Other Resources

Field Intensity Calculation
dBm to Volts to Watts conversion
Free-Space Path Loss Calculator
Useful formulas for RF related conversions

Product Showcase

Double Ridge Guide Horn Antenna

Double Ridge Guide Horn Antenna
  • 700 MHz to 18 GHz
  • Precision machined, Rugged Construction
  • Broadband High Frequency

High gain, low VSWR, input handling capability up to 300 watts CW, and rugged design make this EMC horn antenna excellent for both immunity and emissions testing.


Additional Resource

Field Intensity Calculations

Field Intensity Calculation

Here is a calculation tool to help determ the actual field intensity or power density at a given distance. [more...]

Contact Details

A.H. Systems, inc.
9710 Cozycroft Ave.
Chatsworth, CA 91311

P: (818) 998-0223

F: (818) 998-6892

E: Email