RF Exposure Calculator

FCC has adopted guidelines and procedures for evaluating environmental effects of RF emissions. The new guidelines incorporate two tiers of exposure limits based on whether exposure occurs in an occupational or “controlled” situation or whether the general population is exposed or exposure is in an “uncontrolled” situation. In addition to guidelines for evaluating fixed transmitters, the FCC adopted limits for evaluating exposure from mobile and portable devices, such as cellular telephones and personal communications devices.

To use the RF Exposure Calculator, fill-in the form below with your operating power, antenna gain, and the operating frequency. Depending on how far above ground the RF source is located, you might want to consider ground reflections — and then click “Calculate”.

Click here to get (more) info.


  • Power at Antenna: (Need help with this?) (watts)
  • Mode duty cycle:
  • Transmit duty cycle: (time transmitting)
    You transmit for  minutes then receive for  minutes (and repeat).
  • Antenna Gain (dBi):
  • Operating Frequency (MHz):

 Include Effects of Ground Reflections

Results for a controlled environment:

Maximum Allowed Power Density (mw/cm2):
Minimum Safe Distance (feet):

For an uncontrolled environment:

Maximum Allowed Power Density (mw/cm2):
Minimum Safe Distance (feet):

FCC’s OST Bulletin 65, originally issued in 1985 and revised in 1997, provides additional guidance for evaluating compliance with the latest FCC policies and guidelines and is available here. A supplement for the Amateur Radio Service (Supplement B) is available here. Likewise a supplement for Mobile and Portable equipment (Supplement C) is available here.

The Javascript contained on this page was derived from a public domain BASIC program written by Wayne Overbeck N6NB and published in the January, 1997 issue of CQ VHF, p. 33. Terms: GNU Licence. To view the Javascript that performs the calculation, right-click on this page and select ‘View Page Source’.

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