County outline
Where Nemaha County is located
Area breakdown
Land accounts for 99.4% of Nemaha County’s measured area and water for 0.6%. Its combined area converts to 1,060.9 square kilometers or approximately 262,147 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 407.301 | 1,054.905 | 260,672.6 |
| Water | 2.304 | 5.967 | 1,474.6 |
| Total | 409.605 | 1,060.872 | 262,147.2 |
How Nemaha County compares
By original Census land area, Nemaha County ranks #87 of 93 in Nebraska and #2484 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.708 times the Nebraska county-equivalent median of 575.2 square miles. It accounts for 0.5% of the combined county land area in the state.
See the complete Nebraska ranking · What counts as a county equivalent?
Population and density of Nemaha County
The Census Bureau estimates that 7,102 people lived in Nemaha County on July 1, 2025. That ranks #2,723 of 3,222 county equivalents nationally and #40 of 93 in Nebraska. Since the April 1, 2020 estimates base of 7,077, the population has grown by 25 (+0.4%), compared with +2.9% for Nebraska as a whole.
With 407.3 square miles of land, that is 17 people per square mile (6.7 per km²), placing Nemaha County #2,398 nationally for density and #24 in Nebraska. The median county equivalent has 47 people per square mile; the Nebraska median is 8. Put another way, there are about 37 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 7,086 | 7,004 | 7,024 | 7,088 | 7,104 | 7,102 |
| Change | — | −82 | +20 | +64 | +16 | −2 |
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 Nemaha County
7 incorporated places lie at least partly in Nemaha County. Together they are home to 4,918 people (69.2%); the other 2,184 (30.8%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Auburn city, with 3,498 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Auburn cityCounty seat | 3,498 | +0.5% | 2.18 |
| Peru city | 696 | +2.7% | 0.526 |
| Johnson village | 305 | −0.3% | 0.22 |
| Brownville village | 141 | 0% | 0.654 |
| Brock village | 120 | −1.6% | 0.313 |
| Nemaha village | 112 | 0% | 0.303 |
| Julian village | 46 | 0% | 0.104 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Nemaha County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Nemaha County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.
ZIP codes
13 ZIP Code Tabulation Areas have land in Nemaha County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
68305683206832168348683766837868379684146842168437684426844768448
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 Nemaha County
Nemaha County shares a land border with 6 county equivalents, including 2 in Missouri. It has more land than 1 of them. The largest neighbor is Otoe County (615.6 mi²) and the smallest is Johnson County (376.1 mi²). Together with its neighbors, Nemaha County forms a block of 3,391.9 mi² of land, of which it holds 12%.
| Bordering county equivalent | Land mi² | Size vs. Nemaha | Compare |
|---|---|---|---|
| Otoe County | 615.6 | 1.5× larger | Compare |
| Richardson County | 551.8 | 1.4× larger | Compare |
| Atchison CountyMissouri | 547.3 | 1.3× larger | Compare |
| Holt CountyMissouri | 462.7 | 1.1× larger | Compare |
| Pawnee County | 431.1 | 1.1× larger | Compare |
| Johnson County | 376.1 | 1.1× smaller | Compare |
How big is Nemaha County compared with U.S. states?
Nemaha County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.5 times as much. Nebraska’s county land could hold about 189 areas the size of Nemaha County.
Another way to picture it: the same land area would fill a square about 20.2 miles (32.5 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 Nemaha County?
Nemaha County has more land than 738 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 Nemaha County at #2,549 nationally by total area, 65 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 0.6%, compared with a national county-equivalent median of 1.2% — 0.6 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 Nemaha County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2483 | Chemung County, New York | 407.3 | Compare |
| #2484 | Nemaha County, Nebraska | 407.3 | This county |
| #2485 | Montgomery County, Mississippi | 407 | 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 40.387239, -95.852525. 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: 1,054,904,341 m²; AWATER: 5,966,168 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 Nemaha County?
Nemaha County, Nebraska has 407.3 square miles (1,054.9 km²) of land and 2.304 square miles of water, for a total area of 409.6 square miles. It ranks #2484 of 3,222 U.S. county equivalents by land area.
Is Nemaha County the largest county in Nebraska?
No. Nemaha County ranks #87 of 93 in Nebraska by land area. The largest is Cherry County, with 5,960.1 square miles of land.
What counties border Nemaha County?
Nemaha County shares a land border with Richardson County, Atchison County, Missouri, Otoe County, Johnson County, Pawnee County, and Holt County, Missouri.
What is the population of Nemaha County?
The Census Bureau estimates Nemaha County had 7,102 residents on July 1, 2025, ranking #2,723 of 3,222 county equivalents. That is 17 people per square mile of land.
What is the county seat of Nemaha County?
The county seat of Nemaha County is Auburn.
What cities and towns are in Nemaha County?
Nemaha County has 7 incorporated places. The most populous five are Auburn city, Peru city, Johnson village, Brownville village, and Brock village; 2,184 residents live outside any incorporated place.
Is Nemaha County part of a metropolitan area?
No. Nemaha County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Nemaha County?
13 ZIP Code Tabulation Areas have land in Nemaha 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 Nemaha County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.5 times as much land.
How many acres of land are in Nemaha County?
The land measurement converts to approximately 260,673 acres. Including water, total area is approximately 262,147 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.