County outline
Where Kennebec County is located
Area breakdown
Land accounts for 91.2% of Kennebec County’s measured area and water for 8.8%. Its combined area converts to 2,463.5 square kilometers or approximately 608,752 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 867.507 | 2,246.833 | 555,204.5 |
| Water | 83.668 | 216.699 | 53,547.5 |
| Total | 951.175 | 2,463.532 | 608,752 |
How Kennebec County compares
By original Census land area, Kennebec County ranks #10 of 16 in Maine and #945 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.673 times the Maine county-equivalent median of 1,289.2 square miles. It accounts for 2.8% of the combined county land area in the state.
See the complete Maine ranking · What counts as a county equivalent?
Population and density of Kennebec County
The Census Bureau estimates that 129,067 people lived in Kennebec County on July 1, 2025. That ranks #515 of 3,222 county equivalents nationally and #4 of 16 in Maine. Since the April 1, 2020 estimates base of 124,515, the population has grown by 4,552 (+3.7%), compared with +3.8% for Maine as a whole.
With 867.5 square miles of land, that is 149 people per square mile (57 per km²), placing Kennebec County #777 nationally for density and #5 in Maine. The median county equivalent has 47 people per square mile; the Maine median is 51. Put another way, there are about 4.3 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 124,732 | 125,803 | 127,182 | 128,254 | 128,672 | 129,067 |
| Change | — | +1,071 | +1,379 | +1,072 | +418 | +395 |
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 Kennebec County
Kennebec County is divided into 30 cities and towns. In Maine, county subdivisions are local governments, and together they cover all of the county’s land and residents.
The most populous is Augusta city, with 19,155 residents (14.8% of the county), and it is also the largest by land at 55.1 mi². Among those with at least 1,000 residents in 2020, Pittston town grew fastest since then (+19%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Augusta cityCounty seat | 19,155 | +1.3% | 55.1 | 6.4% |
| Waterville city | 17,579 | +5.4% | 13.5 | 1.6% |
| Winslow town | 8,063 | +1.4% | 36.8 | 4.2% |
| Oakland town | 6,361 | +2% | 25.7 | 3% |
| Gardiner city | 6,206 | +4.1% | 15.7 | 1.8% |
| Winthrop town | 6,158 | +0.6% | 31.2 | 3.6% |
| Sidney town | 4,929 | +6.2% | 42.2 | 4.9% |
| Vassalboro town | 4,647 | +2.8% | 44.3 | 5.1% |
| China town | 4,636 | +5.2% | 49.9 | 5.8% |
| Monmouth town | 4,252 | +4.3% | 34 | 3.9% |
| Litchfield town | 3,797 | +5.8% | 37.4 | 4.3% |
| West Gardiner town | 3,678 | +0.3% | 24.6 | 2.8% |
| Belgrade town | 3,541 | +9% | 43.2 | 5% |
| Pittston town | 3,418 | +19% | 32.2 | 3.7% |
| Clinton town | 3,378 | +0.3% | 43.9 | 5.1% |
Show the other 15 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Farmingdale town | 3,000 | +0.3% | 11.2 |
| Chelsea town | 2,848 | +2.7% | 19.5 |
| Benton town | 2,821 | +3.9% | 28.4 |
| Windsor town | 2,758 | +4.6% | 34.6 |
| Readfield town | 2,730 | +5% | 29.2 |
| Hallowell city | 2,624 | +2.4% | 5.864 |
| Manchester town | 2,492 | +1.4% | 21.4 |
| Albion town | 2,092 | +4.3% | 38.8 |
| Mount Vernon town | 1,843 | +7% | 37.9 |
| Randolph town | 1,780 | +1.9% | 2.135 |
| Fayette town | 1,277 | +9.8% | 29.2 |
| Rome town | 1,184 | +3.3% | 25.4 |
| Wayne town | 1,167 | +3.4% | 19.3 |
| Vienna town | 615 | +5.9% | 24.3 |
| Unity UT | 38 | 0% | 10.4 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Kennebec County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Kennebec County is a central county of the Augusta-Waterville, ME Micropolitan Statistical Area. Kennebec County is the area’s only county equivalent, so the micro area has the same 867.5 square miles of land. By combined land it ranks #236 of 542 micropolitan areas, and #14 by population.
ZIP codes
27 ZIP Code Tabulation Areas have land in Kennebec County; 26 of them have most of their land inside the county, and the others mainly cover neighboring areas.
042590426504284043300434404345043460434704349043500435104352043550435804359043600436304364049010491004917049180492604927049630498804989
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 Kennebec County
Kennebec County shares a land border with 6 county equivalents. It has more land than 4 of them. The largest neighbor is Somerset County (3,924.3 mi²) and the smallest is Sagadahoc County (254 mi²). Together with its neighbors, Kennebec County forms a block of 8,396.8 mi² of land, of which it holds 10.3%.
| Bordering county equivalent | Land mi² | Size vs. Kennebec | Compare |
|---|---|---|---|
| Somerset County | 3,924.3 | 4.5× larger | Compare |
| Franklin County | 1,697 | 2× larger | Compare |
| Waldo County | 730.2 | 1.2× smaller | Compare |
| Androscoggin County | 468 | 1.9× smaller | Compare |
| Lincoln County | 455.9 | 1.9× smaller | Compare |
| Sagadahoc County | 254 | 3.4× smaller | Compare |
How big is Kennebec County compared with U.S. states?
Kennebec County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.2 times as much. Maine’s county land could hold about 36 areas the size of Kennebec County.
Another way to picture it: the same land area would fill a square about 29.5 miles (47.4 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 Kennebec County?
Kennebec County has more land than 2,277 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 Kennebec County at #845 nationally by total area, 100 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.
Its water share is 8.8%, compared with a national county-equivalent median of 1.2% — 7.6 percentage points higher. 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 Kennebec County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #944 | Sangamon County, Illinois | 868.2 | Compare |
| #945 | Kennebec County, Maine | 867.5 | This county |
| #946 | Baylor County, Texas | 867.5 | 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 44.417012, -69.765764. 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: 2,246,831,958 m²; AWATER: 216,698,663 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 Kennebec County?
Kennebec County, Maine has 867.5 square miles (2,246.8 km²) of land and 83.7 square miles of water, for a total area of 951.2 square miles. It ranks #945 of 3,222 U.S. county equivalents by land area.
Is Kennebec County the largest county in Maine?
No. Kennebec County ranks #10 of 16 in Maine by land area. The largest is Aroostook County, with 6,671.2 square miles of land.
What counties border Kennebec County?
Kennebec County shares a land border with Somerset County, Waldo County, Lincoln County, Androscoggin County, Franklin County, and Sagadahoc County.
What is the population of Kennebec County?
The Census Bureau estimates Kennebec County had 129,067 residents on July 1, 2025, ranking #515 of 3,222 county equivalents. That is 149 people per square mile of land.
What is the county seat of Kennebec County?
The county seat of Kennebec County is Augusta.
What cities and towns are in Kennebec County?
Kennebec County has 30 county subdivisions (cities, towns and townships). The most populous five are Augusta city, Waterville city, Winslow town, Oakland town, and Gardiner city.
Is Kennebec County part of a metropolitan area?
Yes. It is a central county of the Augusta-Waterville, ME Micropolitan Statistical Area.
How many ZIP codes are in Kennebec County?
27 ZIP Code Tabulation Areas have land in Kennebec County, and 26 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Kennebec County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.2 times as much land.
How many acres of land are in Kennebec County?
The land measurement converts to approximately 555,204 acres. Including water, total area is approximately 608,752 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.