RF Exposure Screening Calculator
Screening estimate only. Uses a simplified far-field power-density model; it is not a measurement or a determination of FCC compliance. Do not rely on it in the antenna near field, for close-coupled antennas, small loops, unusual antenna patterns, or multi-transmitter sites. Consult current FCC requirements and qualified guidance for safety decisions.

Station inputs

W
Enter transmitter output minus feedline loss. For a conservative screen, use transmitter output if feedline loss is unknown.
%
min
min
Assumes a repeating cycle that begins with transmission. Set receive to 0 for continuous transmission.
dBi
Use gain toward the location being evaluated; convert dBd to dBi by adding 2.15 dB.
MHz

Estimated screening distances

Distances are measured from the antenna and assume the same estimated exposure geometry.

Controlled exposure

Applicable power-density limit: — mW/cm²

Estimated distance: — ft / — m

Uses a 6-minute averaging interval.

Uncontrolled exposure

Applicable power-density limit: — mW/cm²

Estimated distance: — ft / — m

Uses a 30-minute averaging interval.

Method and limitations

This screening tool estimates far-field power density as a function of average power, antenna gain, distance, and selected ground-reflection factor, then solves for the distance at the applicable power-density limit. The limits below follow the power-density bands in 47 CFR § 1.1310. For transmit/receive cycling, time averaging assumes the cycle starts transmitting at the beginning of the averaging window; unknown or irregular operating patterns may require a more conservative assessment.

The simplified inverse-square model is not appropriate for all near-field or antenna geometries and does not model body coupling, antenna pattern nulls/lobes, multiple simultaneous transmitters, shielding, reflections beyond the selected factor, or the actual location/orientation of people. It can either over- or under-estimate actual exposure in particular situations. The result is not a safe-distance guarantee.

For official use, consult current FCC rules, FCC/ARRL material, and a qualified RF-safety professional when needed. This standalone page sends no input data to a server. Bootstrap CSS is fetched from jsDelivr; for completely offline hosting, download and serve a local Bootstrap CSS file.