County outline
Where Eau Claire County is located
Area breakdown
Land accounts for 98.9% of Eau Claire County’s measured area and water for 1.1%. Its combined area converts to 1,671.1 square kilometers or approximately 412,927 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 637.922 | 1,652.21 | 408,270.1 |
| Water | 7.277 | 18.847 | 4,657.3 |
| Total | 645.199 | 1,671.058 | 412,927.4 |
How Eau Claire County compares
By original Census land area, Eau Claire County ranks #44 of 72 in Wisconsin and #1491 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.847 times the Wisconsin county-equivalent median of 753 square miles. It accounts for 1.2% of the combined county land area in the state.
See the complete Wisconsin ranking · What counts as a county equivalent?
Population and density of Eau Claire County
The Census Bureau estimates that 109,033 people lived in Eau Claire County on July 1, 2025. That ranks #587 of 3,222 county equivalents nationally and #14 of 72 in Wisconsin. Since the April 1, 2020 estimates base of 105,706, the population has grown by 3,327 (+3.1%), compared with +1.3% for Wisconsin as a whole.
With 637.9 square miles of land, that is 171 people per square mile (66 per km²), placing Eau Claire County #703 nationally for density and #15 in Wisconsin. The median county equivalent has 47 people per square mile; the Wisconsin median is 51. Put another way, there are about 3.7 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 105,898 | 106,035 | 106,836 | 107,975 | 108,611 | 109,033 |
| Change | — | +137 | +801 | +1,139 | +636 | +422 |
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 Eau Claire County
Eau Claire County is divided into 19 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 Eau Claire city, with 70,095 residents (64.3% of the county). The largest by land is Bridge Creek town, at 102.2 mi², or 16% of the county’s land. Among those with at least 1,000 residents in 2020, Altoona city grew fastest since then (+13.1%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Eau Claire cityCounty seat | 70,095 | +4.2% | 30.1 | 4.7% |
| Altoona city | 9,376 | +13.1% | 5.156 | 0.8% |
| Washington town | 7,478 | −2.3% | 52.7 | 8.3% |
| Pleasant Valley town | 3,878 | +2.2% | 54.2 | 8.5% |
| Seymour town | 3,261 | −2.4% | 31 | 4.9% |
| Union town | 2,556 | −4.4% | 26.6 | 4.2% |
| Bridge Creek town | 2,191 | −0.6% | 102.2 | 16% |
| Brunswick town | 1,929 | −1.7% | 36.6 | 5.7% |
| Augusta city | 1,483 | −5.8% | 2.216 | 0.3% |
| Fall Creek village | 1,390 | −2.5% | 2.049 | 0.3% |
| Lincoln town | 1,093 | −2.8% | 57.9 | 9.1% |
| Ludington town | 1,037 | −2.3% | 45.8 | 7.2% |
| Drammen town | 780 | −2.3% | 36 | 5.6% |
| Clear Creek town | 749 | −3.9% | 36 | 5.6% |
| Fairchild town | 445 | −1.1% | 34.6 | 5.4% |
Show the other 4 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Fairchild village | 435 | −3.3% | 1.455 |
| Wilson town | 435 | +1.4% | 47.7 |
| Otter Creek town | 422 | −1.9% | 35.5 |
| Lake Hallie village | 0 | — | 0.102 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Eau Claire County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Eau Claire County is a central county of the Eau Claire, WI Metropolitan Statistical Area. Its 2 county equivalents have 176,647 residents on 1,646.4 square miles of land; Eau Claire County accounts for 38.7% of the land and 61.7% of the residents. By combined land it ranks #194 of 393 metropolitan areas, and #258 by population. It belongs to the Eau Claire-Menomonie, WI Combined Statistical Area.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Eau Claire County | 109,033 | 637.9 |
| Chippewa County | 67,614 | 1,008.4 |
ZIP codes
15 ZIP Code Tabulation Areas have land in Eau Claire County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
547015470354720547225472654727547295473854739547415474254755547585476854770
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 Eau Claire County
Eau Claire County shares a land border with 7 county equivalents. It has more land than 1 of them. The largest neighbor is Clark County (1,209.7 mi²) and the smallest is Pepin County (232 mi²). Together with its neighbors, Eau Claire County forms a block of 6,334.9 mi² of land, of which it holds 10.1%.
| Bordering county equivalent | Land mi² | Size vs. Eau Claire | Compare |
|---|---|---|---|
| Clark County | 1,209.7 | 1.9× larger | Compare |
| Chippewa County | 1,008.4 | 1.6× larger | Compare |
| Jackson County | 987.9 | 1.5× larger | Compare |
| Dunn County | 850.2 | 1.3× larger | Compare |
| Trempealeau County | 733 | 1.1× larger | Compare |
| Buffalo County | 675.8 | 1.1× larger | Compare |
| Pepin County | 232 | 2.7× smaller | Compare |
How big is Eau Claire County compared with U.S. states?
Eau Claire County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.6 times as much. Wisconsin’s county land could hold about 85 areas the size of Eau Claire County.
Another way to picture it: the same land area would fill a square about 25.3 miles (40.6 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 Eau Claire County?
Eau Claire County has more land than 1,731 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 Eau Claire County at #1,589 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 1.1%, compared with a national county-equivalent median of 1.2%. The two percentages are within 0.1 percentage points of each other. 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 Eau Claire County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1490 | Jasper County, Missouri | 638.5 | Compare |
| #1491 | Eau Claire County, Wisconsin | 637.9 | This county |
| #1492 | Hardee County, Florida | 637.6 | 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 44.726355, -91.286414. 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: 1,652,211,254 m²; AWATER: 18,848,555 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 Eau Claire County?
Eau Claire County, Wisconsin has 637.9 square miles (1,652.2 km²) of land and 7.277 square miles of water, for a total area of 645.2 square miles. It ranks #1491 of 3,222 U.S. county equivalents by land area.
Is Eau Claire County the largest county in Wisconsin?
No. Eau Claire County ranks #44 of 72 in Wisconsin by land area. The largest is Marathon County, with 1,545.2 square miles of land.
What counties border Eau Claire County?
Eau Claire County shares a land border with Chippewa County, Clark County, Trempealeau County, Dunn County, Jackson County, Buffalo County, and Pepin County.
What is the population of Eau Claire County?
The Census Bureau estimates Eau Claire County had 109,033 residents on July 1, 2025, ranking #587 of 3,222 county equivalents. That is 171 people per square mile of land.
What is the county seat of Eau Claire County?
The county seat of Eau Claire County is Eau Claire.
What cities and towns are in Eau Claire County?
Eau Claire County has 19 county subdivisions (cities, towns and townships). The most populous five are Eau Claire city, Altoona city, Washington town, Pleasant Valley town, and Seymour town.
Is Eau Claire County part of a metropolitan area?
Yes. It is a central county of the Eau Claire, WI Metropolitan Statistical Area, which has 2 county equivalents and 176,647 residents.
How many ZIP codes are in Eau Claire County?
15 ZIP Code Tabulation Areas have land in Eau Claire County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Eau Claire County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.6 times as much land.
How many acres of land are in Eau Claire County?
The land measurement converts to approximately 408,270 acres. Including water, total area is approximately 412,927 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.