A routine RF exposure evaluation, the kind every US station has needed since the FCC dropped the amateur exemption in 2021. Set your band, power, and antenna, and this gives the maximum permissible exposure limits and the minimum safe distance for both exposure categories. All math runs in your browser. Nothing is stored. This is a planning aid, not a substitute for your official station evaluation.
Occupational / controlled covers people who know the antenna is there and can move away: you and your household. Averaged over 6 minutes, higher limit.
General public / uncontrolled covers people who may not know it is there: neighbors, passersby. Averaged over 30 minutes, lower limit. This is usually the one that sets your required distance.
The estimate assumes a person standing in the main beam at the given distance, in the far field. Close to the antenna and on the low bands you can be in the near field, where this far-field number is approximate and tends to run conservative (it overstates the field). Ground reflection bumps the estimate to a worst case where the reflected wave adds to the direct wave.
Limits follow FCC 47 CFR 1.1310 and the method in FCC OET Bulletin 65. Use the full OET-65 procedure or a recognized calculator for the record you keep on file.