County outline
Where Iowa County is located
Area breakdown
Land accounts for 99.3% of Iowa County’s measured area and water for 0.7%. Its combined area converts to 1,989.2 square kilometers or approximately 491,554 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 762.698 | 1,975.379 | 488,126.7 |
| Water | 5.355 | 13.869 | 3,427.2 |
| Total | 768.053 | 1,989.248 | 491,553.9 |
How Iowa County compares
By original Census land area, Iowa County ranks #35 of 72 in Wisconsin and #1144 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.013 times the Wisconsin county-equivalent median of 753 square miles. It accounts for 1.4% of the combined county land area in the state.
See the complete Wisconsin ranking · What counts as a county equivalent?
Population and density of Iowa County
The Census Bureau estimates that 23,951 people lived in Iowa County on July 1, 2025. That ranks #1,700 of 3,222 county equivalents nationally and #48 of 72 in Wisconsin. Since the April 1, 2020 estimates base of 23,713, the population has grown by 238 (+1%), compared with +1.3% for Wisconsin as a whole.
With 762.7 square miles of land, that is 31 people per square mile (12 per km²), placing Iowa County #1,963 nationally for density and #51 in Wisconsin. The median county equivalent has 47 people per square mile; the Wisconsin median is 51. Put another way, there are about 20 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 23,716 | 23,809 | 23,950 | 23,913 | 23,975 | 23,951 |
| Change | — | +93 | +141 | −37 | +62 | −24 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Iowa County
Iowa County is divided into 29 cities and towns. In Wisconsin, county subdivisions are local governments, and together they cover all of the county’s land and residents.
The most populous is Dodgeville city, with 5,076 residents (21.2% of the county). The largest by land is Dodgeville town, at 89.3 mi², or 11.7% of the county’s land. Among those with at least 1,000 residents in 2020, Brigham town grew fastest since then (+3.1%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Dodgeville cityCounty seat | 5,076 | +1.8% | 4.085 | 0.5% |
| Mineral Point city | 2,555 | −1% | 3.136 | 0.4% |
| Dodgeville townCounty seat | 1,610 | +1.8% | 89.3 | 11.7% |
| Arena town | 1,496 | +0.9% | 78 | 10.2% |
| Barneveld village | 1,333 | +0.8% | 2.099 | 0.3% |
| Brigham town | 1,061 | +3.1% | 63.4 | 8.3% |
| Mineral Point town | 984 | +0.8% | 58.9 | 7.7% |
| Arena village | 916 | +8% | 1.156 | 0.2% |
| Highland village | 860 | −1.6% | 1.138 | 0.1% |
| Highland town | 738 | +2.9% | 64.6 | 8.5% |
| Linden town | 737 | −2.3% | 60.7 | 8% |
| Ridgeway village | 650 | +3.5% | 1.283 | 0.2% |
| Moscow town | 581 | 0% | 41.3 | 5.4% |
| Mifflin town | 577 | +2.7% | 50.6 | 6.6% |
| Ridgeway town | 573 | +0.7% | 42.7 | 5.6% |
Show the other 14 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Avoca village | 547 | −1.6% | 2.251 |
| Linden village | 498 | −1.8% | 0.78 |
| Cobb village | 481 | −0.4% | 1.028 |
| Waldwick town | 453 | −1.3% | 41.9 |
| Pulaski town | 359 | −0.6% | 43.3 |
| Eden town | 332 | −0.9% | 35 |
| Wyoming town | 324 | +2.5% | 39.7 |
| Clyde town | 305 | +4.8% | 34.1 |
| Hollandale village | 301 | −3.2% | 0.729 |
| Rewey village | 252 | −1.9% | 0.507 |
| Blanchardville village | 205 | +3% | 0.155 |
| Montfort village | 78 | −2.5% | 0.043 |
| Muscoda village | 57 | 0% | 0.528 |
| Livingston village | 12 | 0% | 0.211 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Iowa County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Iowa County is an outlying county of the Madison, WI Metropolitan Statistical Area. Its 4 county equivalents have 709,685 residents on 3,308.8 square miles of land; Iowa County accounts for 23.1% of the land and 3.4% of the residents. By combined land it ranks #90 of 393 metropolitan areas, and #87 by population. It belongs to the Madison-Janesville-Beloit, WI Combined Statistical Area.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Dane County | 590,375 | 1,196.5 |
| Columbia County | 58,132 | 765.6 |
| Green County | 37,227 | 584 |
| Iowa County | 23,951 | 762.7 |
ZIP codes
19 ZIP Code Tabulation Areas have land in Iowa County; 11 of them have most of their land inside the county, and the others mainly cover neighboring areas.
53503535065350753516535175352653533535435354453553535545356053565535695357353580535825358853818
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Iowa County
Iowa County shares a land border with 6 county equivalents. It has more land than 3 of them. The largest neighbor is Dane County (1,196.5 mi²) and the smallest is Green County (584 mi²). Together with its neighbors, Iowa County forms a block of 5,742.2 mi² of land, of which it holds 13.3%.
| Bordering county equivalent | Land mi² | Size vs. Iowa | Compare |
|---|---|---|---|
| Dane County | 1,196.5 | 1.6× larger | Compare |
| Grant County | 1,147.6 | 1.5× larger | Compare |
| Sauk County | 831.6 | 1.1× larger | Compare |
| Lafayette County | 633.6 | 1.2× smaller | Compare |
| Richland County | 586.2 | 1.3× smaller | Compare |
| Green County | 584 | 1.3× smaller | Compare |
How big is Iowa County compared with U.S. states?
Iowa County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.4 times as much. Wisconsin’s county land could hold about 71 areas the size of Iowa County.
Another way to picture it: the same land area would fill a square about 27.6 miles (44.4 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Iowa County?
Iowa County has more land than 2,078 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Iowa County at #1,242 nationally by total area, 98 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 0.7%, compared with a national county-equivalent median of 1.2% — 0.5 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Iowa County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1143 | Duval County, Florida | 762.7 | Compare |
| #1144 | Iowa County, Wisconsin | 762.7 | This county |
| #1145 | Onslow County, North Carolina | 762.1 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 43.001021, -90.133691. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,975,379,600 m²; AWATER: 13,870,581 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Iowa County?
Iowa County, Wisconsin has 762.7 square miles (1,975.4 km²) of land and 5.355 square miles of water, for a total area of 768.1 square miles. It ranks #1144 of 3,222 U.S. county equivalents by land area.
Is Iowa County the largest county in Wisconsin?
No. Iowa County ranks #35 of 72 in Wisconsin by land area. The largest is Marathon County, with 1,545.2 square miles of land.
What counties border Iowa County?
Iowa County shares a land border with Lafayette County, Grant County, Dane County, Sauk County, Richland County, and Green County.
What is the population of Iowa County?
The Census Bureau estimates Iowa County had 23,951 residents on July 1, 2025, ranking #1,700 of 3,222 county equivalents. That is 31 people per square mile of land.
What is the county seat of Iowa County?
The county seat of Iowa County is Dodgeville.
What cities and towns are in Iowa County?
Iowa County has 29 county subdivisions (cities, towns and townships). The most populous five are Dodgeville city, Mineral Point city, Dodgeville town, Arena town, and Barneveld village.
Is Iowa County part of a metropolitan area?
Yes. It is an outlying county of the Madison, WI Metropolitan Statistical Area, which has 4 county equivalents and 709,685 residents.
How many ZIP codes are in Iowa County?
19 ZIP Code Tabulation Areas have land in Iowa County, and 11 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Iowa County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.4 times as much land.
How many acres of land are in Iowa County?
The land measurement converts to approximately 488,127 acres. Including water, total area is approximately 491,554 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.