Wisconsin County Map with All 72 Counties and Population
| County | Population | Land area | Polygon area | Difference | Density | Share of state |
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County boundaries and land area: United States Census Bureau, TIGERweb, public domain. Population: 2020 Census of Population and Housing. County seats: Wikipedia. Aerial imagery: United States Geological Survey, The National Map, public domain.
How to use this map
Pick a map type along the top and the map redraws. Counties colours all 72 so no two neighbours share a fill, Density shades them by people per square kilometre, Satellite swaps the flat colours for real imagery of the state, and Blank outline gives you black on white for printing. Click any county, or any row in the table, and its figures appear in the Selection panel: population, land area, density and county seat.
Names are drawn where there is room for them. With 72 counties, some are too small at this scale to label without printing one name on top of another, so the label is dropped rather than made illegible. Clicking still identifies every one, and the table lists them all.
Switch between metric and imperial with the Units control. Everything on the page follows it, including the downloads.
Where the data comes from
Boundaries and land areas come from the United States Census Bureau through the TIGERweb service, which is the same geography the Bureau uses for its own published tables. Populations are 2020 Census counts, and county seats come from the published county list.
The check that matters is the total. The 72 populations sum to 5,893,718, which is the published state figure, and the land areas sum to 140,295 square kilometres. If a set of figures for Wisconsin does not reach those totals, it is mixing census years or dropping units, and both are easy to do without noticing.
Aerial imagery, and how it is fitted to the map
The Satellite map type replaces the flat colours with real aerial imagery from the United States Geological Survey, taken from The National Map. Most of it comes from the National Agriculture Imagery Program, flown at one metre resolution or better, which is far sharper than a global satellite composite at this scale.
The imagery arrives as a plain latitude and longitude grid while this map is drawn in Lambert conformal conic. Laying one straight over the other would leave the coastline and the county boundaries drifting apart as you move north. So every pixel is converted back to a latitude and longitude and the matching pixel is read from the source image, which puts both in the same projection. It is then clipped to the outline, so the map shows Wisconsin rather than a rectangle of the surrounding region.
The imagery is public domain, as work of the United States government, so it can travel with the map when you download it. That is also why this is USGS imagery rather than the commercial layers on the big mapping sites, which are licensed from private operators and cannot be redistributed through a download button.
Two practical notes. The imagery takes a second or two to appear the first time, because it is fetched and reprojected on the spot. And although the source is flown at one metre, a whole state on one screen works out coarser than that, so you can read terrain, rivers, farmland and the edges of built up areas rather than individual buildings.
A check you can repeat on paper
Take Milwaukee, the most populous county in the state.
The Census Bureau gives it 939,489 people and 625 square kilometres of land. Divide one by the other and you get 1502.3 people per square kilometre.
Select Milwaukee and the Selection panel reads 1502.3. Switch to imperial and it becomes 3890.9 per square mile.
Now add the 72 land areas in the table. They come to 140,295 square kilometres, and the populations to 5,893,718.
What the numbers show
9 of the 72 hold half of Wisconsin between them: Milwaukee, Dane, Waukesha, Brown, Racine, Outagamie, Winnebago, Kenosha, Rock. They cover 9.1 percent of the land, leaving the other 63 to hold the remaining half.
The densest is Milwaukee at 1502.3 people per square kilometre, then Waukesha at 285.8. At the other end, Iron runs at 3.1 and Forest at 3.5. That is a spread of roughly 481 to one across a single state.
Marathon is the largest by area at 4,002 square kilometres and holds 138,013 people, while Pepin is the smallest at 601. Wisconsin as a whole sits at 42.0 people per square kilometre, against a national figure of 36.2.
Mistakes that catch people out
Mixing census years. Populations from different vintages look identical on the page and only reveal themselves when the total misses 5,893,718. Every figure here is 2020.
Treating the drawn area as land. Every county outline includes its inland water. Milwaukee is the clearest case here, enclosing about 391 percent more area than its land figure. Every density on this page is computed on land area, not on the area you see drawn, and the Selection panel shows both.
Reading the colours as data. On the counties view the fills only ensure that neighbours differ, so a colour carries no meaning at all. The Density view is the one where colour maps to a number.
Related Calculators and Reference
- United States Map: all fifty states and the District of Columbia with satellite imagery, cities and rivers.
- US State Maps: every state with its capital, population, land area, density and county count.
- Texas County Map: the largest set of counties in the country at 254.
- United States Census Bureau, Geography: the source of the boundaries and land areas used here.
- The National Map viewer: the USGS browser behind the aerial imagery on this page.
County boundaries and land area: United States Census Bureau, TIGERweb, public domain. Population: 2020 Census of Population and Housing. Aerial imagery: United States Geological Survey, The National Map, public domain.
