County outline
Where Linn County is located
Area breakdown
Land accounts for 98.9% of Linn County’s measured area and water for 1.1%. Its combined area converts to 1,876.9 square kilometers or approximately 463,788 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 717.013 | 1,857.055 | 458,888.3 |
| Water | 7.656 | 19.829 | 4,899.8 |
| Total | 724.669 | 1,876.884 | 463,788.2 |
How Linn County compares
By original Census land area, Linn County ranks #10 of 99 in Iowa and #1260 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.259 times the Iowa county-equivalent median of 569.6 square miles. It accounts for 1.3% of the combined county land area in the state.
See the complete Iowa ranking · What counts as a county equivalent?
Population and density of Linn County
The Census Bureau estimates that 232,028 people lived in Linn County on July 1, 2025. That ranks #313 of 3,222 county equivalents nationally and #2 of 99 in Iowa. Since the April 1, 2020 estimates base of 230,291, the population has grown by 1,737 (+0.8%), compared with +1.5% for Iowa as a whole.
With 717 square miles of land, that is 324 people per square mile (125 per km²), placing Linn County #482 nationally for density and #3 in Iowa. The median county equivalent has 47 people per square mile; the Iowa median is 26. Put another way, there are about 2 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 230,405 | 229,479 | 228,878 | 228,775 | 230,389 | 232,028 |
| Change | — | −926 | −601 | −103 | +1,614 | +1,639 |
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 Linn County
18 incorporated places lie at least partly in Linn County. Together they are home to 212,902 people (91.8%); the other 19,126 (8.2%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Cedar Rapids city, with 137,935 residents in the county. Among places with at least 1,000 residents in 2020, Palo city grew fastest since then (+9.9%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Cedar Rapids cityCounty seat | 137,935 | +0.1% | 74.8 |
| Marion city | 42,732 | +2.8% | 18.1 |
| Hiawatha city | 7,432 | +3.4% | 4.771 |
| Mount Vernon city | 4,514 | −0.5% | 3.734 |
| Robins city | 3,366 | +0.1% | 5.993 |
| Fairfax city | 2,925 | +3.1% | 3.626 |
| Center Point city | 2,572 | −0.5% | 2.727 |
| Ely city | 2,366 | +1.2% | 1.686 |
| Lisbon city | 2,239 | +0.3% | 2.122 |
| Palo city | 1,551 | +9.9% | 1.197 |
| Central City city | 1,253 | −1% | 1.074 |
| Springville city | 1,160 | −0.2% | 2.413 |
| Coggon city | 688 | −2.3% | 0.71 |
| Alburnett city | 675 | +0.1% | 0.756 |
| Walker city | 674 | −1.9% | 0.749 |
Show the other 3 places
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Walford cityAlso in 1 other county | 397 | −3.2% | 1.04 |
| Bertram city | 267 | −0.7% | 1.534 |
| Prairieburg city | 156 | −0.6% | 0.448 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Linn County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Linn County is a central county of the Cedar Rapids, IA Metropolitan Statistical Area. Its 3 county equivalents have 279,285 residents on 2,008.7 square miles of land; Linn County accounts for 35.7% of the land and 83.1% of the residents. By combined land it ranks #157 of 393 metropolitan areas, and #184 by population. It belongs to the Cedar Rapids-Iowa City, IA Combined Statistical Area.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Linn County | 232,028 | 717 |
| Benton County | 26,004 | 716.1 |
| Jones County | 21,253 | 575.6 |
ZIP codes
30 ZIP Code Tabulation Areas have land in Linn County; 21 of them have most of their land inside the county, and the others mainly cover neighboring areas.
522025220352205522135221452218522195222752228522335225352302523055231052314523245232852332523365233852341523445235152352524015240252403524045240552411
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 Linn County
Linn County shares a land border with 6 county equivalents. It has more land than every one of them. The largest neighbor is Benton County (716.1 mi²) and the smallest is Buchanan County (571.1 mi²). Together with its neighbors, Linn County forms a block of 4,350 mi² of land, of which it holds 16.5%.
| Bordering county equivalent | Land mi² | Size vs. Linn | Compare |
|---|---|---|---|
| Benton County | 716.1 | about the same | Compare |
| Johnson County | 613 | 1.2× smaller | Compare |
| Cedar County | 579.5 | 1.2× smaller | Compare |
| Delaware County | 577.7 | 1.2× smaller | Compare |
| Jones County | 575.6 | 1.2× smaller | Compare |
| Buchanan County | 571.1 | 1.3× smaller | Compare |
How big is Linn County compared with U.S. states?
Linn 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. Iowa’s county land could hold about 78 areas the size of Linn County.
Another way to picture it: the same land area would fill a square about 26.8 miles (43.1 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 Linn County?
Linn County has more land than 1,962 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 Linn County at #1,339 nationally by total area, 79 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% — 0.1 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 Linn County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1259 | Red Willow County, Nebraska | 717.2 | Compare |
| #1260 | Linn County, Iowa | 717 | This county |
| #1261 | Contra Costa County, California | 716.9 | 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 42.076074, -91.596206. 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: 1,857,054,773 m²; AWATER: 19,828,878 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 Linn County?
Linn County, Iowa has 717 square miles (1,857.1 km²) of land and 7.656 square miles of water, for a total area of 724.7 square miles. It ranks #1260 of 3,222 U.S. county equivalents by land area.
Is Linn County the largest county in Iowa?
No. Linn County ranks #10 of 99 in Iowa by land area. The largest is Kossuth County, with 972.7 square miles of land.
What counties border Linn County?
Linn County shares a land border with Benton County, Jones County, Johnson County, Buchanan County, Delaware County, and Cedar County.
What is the population of Linn County?
The Census Bureau estimates Linn County had 232,028 residents on July 1, 2025, ranking #313 of 3,222 county equivalents. That is 324 people per square mile of land.
What is the county seat of Linn County?
The county seat of Linn County is Cedar Rapids.
What cities and towns are in Linn County?
Linn County has 18 incorporated places. The most populous five are Cedar Rapids city, Marion city, Hiawatha city, Mount Vernon city, and Robins city; 19,126 residents live outside any incorporated place.
Is Linn County part of a metropolitan area?
Yes. It is a central county of the Cedar Rapids, IA Metropolitan Statistical Area, which has 3 county equivalents and 279,285 residents.
How many ZIP codes are in Linn County?
30 ZIP Code Tabulation Areas have land in Linn County, and 21 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Linn 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 Linn County?
The land measurement converts to approximately 458,888 acres. Including water, total area is approximately 463,788 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.