County outline
Where Worth County is located
Area breakdown
Land accounts for 99.5% of Worth County’s measured area and water for 0.5%. Its combined area converts to 1,041 square kilometers or approximately 257,242 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 400.123 | 1,036.314 | 256,078.7 |
| Water | 1.818 | 4.709 | 1,163.5 |
| Total | 401.941 | 1,041.022 | 257,242.2 |
How Worth County compares
By original Census land area, Worth County ranks #96 of 99 in Iowa and #2528 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.703 times the Iowa county-equivalent median of 569.6 square miles. It accounts for 0.7% of the combined county land area in the state.
See the complete Iowa ranking · What counts as a county equivalent?
Population and density of Worth County
The Census Bureau estimates that 7,338 people lived in Worth County on July 1, 2025. That ranks #2,708 of 3,222 county equivalents nationally and #89 of 99 in Iowa. Since the April 1, 2020 estimates base of 7,446, the population has declined by 108 (−1.5%), compared with +1.5% for Iowa as a whole.
With 400.1 square miles of land, that is 18 people per square mile (7.1 per km²), placing Worth County #2,377 nationally for density and #77 in Iowa. The median county equivalent has 47 people per square mile; the Iowa median is 26. Put another way, there are about 35 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 7,437 | 7,385 | 7,330 | 7,330 | 7,300 | 7,338 |
| Change | — | −52 | −55 | 0 | −30 | +38 |
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 Worth County
7 incorporated places lie at least partly in Worth County. Together they are home to 4,476 people (61%); the other 2,862 (39%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Northwood city, with 2,056 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Northwood cityCounty seat | 2,056 | −0.7% | 3.986 |
| Manly city | 1,239 | −1.7% | 1.414 |
| Fertile city | 301 | −1.6% | 0.941 |
| Kensett city | 258 | −0.4% | 1.013 |
| Grafton city | 212 | −1.9% | 0.321 |
| Joice city | 207 | −1.9% | 1.068 |
| Hanlontown city | 203 | −1.9% | 0.969 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Worth County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Worth County is an outlying county of the Mason City, IA Micropolitan Statistical Area. Its 2 county equivalents have 49,710 residents on 968.4 square miles of land; Worth County accounts for 41.3% of the land and 14.8% of the residents. By combined land it ranks #190 of 542 micropolitan areas, and #228 by population.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Cerro Gordo County | 42,372 | 568.3 |
| Worth County | 7,338 | 400.1 |
ZIP codes
10 ZIP Code Tabulation Areas have land in Worth County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.
50434504405044450446504485045050456504595046450472
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 Worth County
Worth County shares a land border with 5 county equivalents, including 2 in Minnesota. Each of them has more land than Worth County. The largest neighbor is Mower County (711.3 mi²) and the smallest is Winnebago County (400.5 mi²). Together with its neighbors, Worth County forms a block of 3,256.7 mi² of land, of which it holds 12.3%.
| Bordering county equivalent | Land mi² | Size vs. Worth | Compare |
|---|---|---|---|
| Mower CountyMinnesota | 711.3 | 1.8× larger | Compare |
| Freeborn CountyMinnesota | 707.2 | 1.8× larger | Compare |
| Cerro Gordo County | 568.3 | 1.4× larger | Compare |
| Mitchell County | 469.3 | 1.2× larger | Compare |
| Winnebago County | 400.5 | about the same | Compare |
How big is Worth County compared with U.S. states?
Worth County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.6 times as much. Iowa’s county land could hold about 140 areas the size of Worth County.
Another way to picture it: the same land area would fill a square about 20 miles (32.2 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 Worth County?
Worth County has more land than 694 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 Worth County at #2,594 nationally by total area, 66 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 0.5%, compared with a national county-equivalent median of 1.2% — 0.7 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 Worth County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2527 | Long County, Georgia | 400.4 | Compare |
| #2528 | Worth County, Iowa | 400.1 | This county |
| #2529 | Alcorn County, Mississippi | 400 | 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 43.373491, -93.248533. 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: 1,036,314,910 m²; AWATER: 4,709,127 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 Worth County?
Worth County, Iowa has 400.1 square miles (1,036.3 km²) of land and 1.818 square miles of water, for a total area of 401.9 square miles. It ranks #2528 of 3,222 U.S. county equivalents by land area.
Is Worth County the largest county in Iowa?
No. Worth County ranks #96 of 99 in Iowa by land area. The largest is Kossuth County, with 972.7 square miles of land.
What counties border Worth County?
Worth County shares a land border with Cerro Gordo County, Freeborn County, Minnesota, Winnebago County, Mitchell County, and Mower County, Minnesota.
What is the population of Worth County?
The Census Bureau estimates Worth County had 7,338 residents on July 1, 2025, ranking #2,708 of 3,222 county equivalents. That is 18 people per square mile of land.
What is the county seat of Worth County?
The county seat of Worth County is Northwood.
What cities and towns are in Worth County?
Worth County has 7 incorporated places. The most populous five are Northwood city, Manly city, Fertile city, Kensett city, and Grafton city; 2,862 residents live outside any incorporated place.
Is Worth County part of a metropolitan area?
Yes. It is an outlying county of the Mason City, IA Micropolitan Statistical Area, which has 2 county equivalents and 49,710 residents.
How many ZIP codes are in Worth County?
10 ZIP Code Tabulation Areas have land in Worth County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Worth County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.6 times as much land.
How many acres of land are in Worth County?
The land measurement converts to approximately 256,079 acres. Including water, total area is approximately 257,242 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.