How we work it out
Every number on this site comes from a public source we can name and date. Here is what we use, and what is still being built.
Stations and towers: the FCC
Station locations, channels, power and antenna heights come from the FCC's Licensing and Management System (LMS) public database, currently the data of . We include every licensed class: full-power, Class A, low-power and translator stations, plus stations that are silent or at reduced power.
For each station we use its newest granted licence rather than unbuilt construction permits, so we show where a station transmits today. We check every tower location against the FCC's own published coverage contours; in our latest check, every station with a published contour matched the FCC's transmitter position to within 50 metres.
Networks and subchannels
Which network each channel carries comes from our affiliations dataset, built from Wikipedia (used under CC BY-SA 4.0; see credits), the network field stations file with the FCC, and station websites. Where no source confirms a network we say "network unknown" instead of guessing.
Where a station has switched to NextGen TV (ATSC 3.0), we list each channel once under the station it belongs to and show which partner station carries the version any TV can receive.
Signal predictions
For every US ZIP code we predict each station's signal over the real terrain between its tower and the places people live, using USGS elevation data, each station's height, power and filed antenna pattern, and the FCC's own planning standards for TV reception. That is 79 million tower-to-home paths for the FCC data of November 3, 2026.
How we check it: we ran a test set of 52 ZIP codes across 7 kinds of terrain (flat, mountain, valley and ridge, shadowed basin, coast, dense city, island) through FCC TVStudy, the software the FCC uses for TV coverage studies. Across 5,652 station-and-ZIP checks, whether a station reaches the ZIP matched 99.5%; the full answer (all, part or none of the ZIP) matched 99.2%; where either side found only part of the ZIP covered, the yes/no answer matched 93%. We never called a station "covers the whole ZIP" where TVStudy found it reaches none of it. This compares two prediction models; we tuned ours against this same set, and we have not yet compared it with real channel scans.
Limits: predictions are for a typical home in the ZIP with an outdoor antenna about 30 ft up; trees, buildings and your exact spot can change things. Where terrain makes a station hard to call we mark it "May vary". Canadian and Mexican stations are not included yet. A channel scan on your TV is always the final word.
Towns and directions
Directions and distances from towns use US Census Bureau place locations and population estimates. Distances are straight lines from each town's Census centre point to the tower.
Market areas
Each market page covers the counties where that market's full-power stations reach the most people, judged from the FCC's published coverage contours, using the FCC's list of TV markets. It is our own assignment, not a ratings company's market map, so a few border counties may sit in a different market than you expect. Market figures are shares of the people living in those counties' ZIP codes.
Changelog
Current prediction model: 2026-11-11.4, on FCC licence data of 2026-11-03.
- Network affiliations corrected for 12 stations after checking each station’s own website and recent news (for example KMOV St. Louis, still CBS on 4.1 with ABC added on 32.1).
- One rule for the antenna advice on every page; VHF channels never count as “indoor”; channel counts leave out duplicate simulcasts and NextGen-only channels.
- model 2026-11-11.4 National run for every US ZIP code: each station’s reach from its FCC coverage area, terrain at about 30 m detail, and each antenna’s filed pattern. Matches FCC TVStudy 99.5% on our 52-ZIP test set.
How often it updates
We currently use FCC licence data of November 3, 2026, refreshed by hand for now. Every page and every ZIP answer shows the date of its data.