The geographic center of every US state, recalculated

Method

What “center” means here

We use the USGS’s own definition: the center of gravity of the surface, the point where a cut-out of the state, of uniform thickness, would balance. We compute it as the area centroid on the GRS80 ellipsoid (the one used by NAD83) in a Lambert azimuthal equal-area projection centered on the result itself, which preserves areas.

Like the USGS, we leave islands out: the main center is that of the land connected by land to the continent in the Census boundaries (plus Point Roberts, an enclave in Canada). For states with islands we also give the center including them. Hawaii has no mainland: its center is that of all its islands, and we also give the center of the Island of Hawaiʻi.

Data

The boundaries are the counties in the Census Bureau’s 2025 Cartographic Boundary Files at 1:500,000, clipped to the shoreline and the Great Lakes: each state is built from its counties. For each center we give the county it falls in, the nearest GNIS populated place and the nearest Census place of over 1,000 people, with the distance and direction from them.

Every center was checked against a second, independent calculation, the center of gravity on the sphere with the simplified boundaries the website uses: the median difference is about 100 m, and the largest about 4.5 km, in Alaska, because of its size. For the whole country (49 and 50 states, from Hawaii to Maine) the two ways of computing the center differ by about 20 km: at that scale, the center depends on the definition.

The USGS centers

The USGS table was first published in 1923 (Bulletin 689, by Edward M. Douglas), revised in 1930 and 1966 (Bulletin 1212, by Franklin K. Van Zandt, now with Alaska and Hawaii) and still appears in Elevations and Distances in the United States. The USGS itself warns that there is no generally accepted definition of a geographic center and that its positions are approximations. The center of the 48 states, near Lebanon, Kansas, was found by the Coast and Geodetic Survey in 1918 by balancing a cardboard cut-out.

The USGS describes each center as “so many miles in some direction from a town”. To compare, we place it from that town’s GNIS point; over long distances the margin is several miles, because the direction has only 16 compass points.

Why they differ

The USGS centers were worked out a century ago on paper maps, with the techniques and precision of the time, and rounded to the mile. Boundaries have also changed: coastlines and rivers are now mapped in far more detail. The result also depends on which water counts as part of the state (the Census clips the coast and the Great Lakes, but not inland lakes) and on which islands are left out.

Large states are the most sensitive: a small difference in shape moves their center by tens of miles. Using another modern method, Peter Rogerson (University at Buffalo) placed the center of the 48 states near Agra, Kansas, in 2015, 27.9 miles from Lebanon; ours is 5.5 mi from Agra.

How we work with data across the site