How to list the counties in a radius
This page opens with a 100-mile circle and the Counties inside a circle panel open. Search a town or type coordinates to move the center, or click the map; type a different radius above the map to change the circle. The panel lists every county whose internal point is inside the circle, nearest first, with its state and straight-line distance. Download CSV saves the county, state, coordinates and distance; Copy list copies the county names.
With several circles on the map (for example rings of 50, 100 and 150 miles typed as 50, 100, 150), pick the circle to list from the Circle menu.
Reading the list
Counties vary enormously in size. East of the Mississippi most counties are a few hundred square miles and their internal point is a good stand-in for the whole county. In the West, a county such as San Bernardino (over 20,000 square miles) or the census areas of Alaska can be larger than a 50-mile circle, so a county can cover part of the circle without its point being inside, and the list will leave it out. Widen the radius when in doubt.
The data is the US Census Bureau’s 2025 Gazetteer of counties, a public-domain file of every county and county equivalent with its land area and internal point. It is part of this site and loads only on this page, about 36 KB compressed.