Cumberland County area

Population and density of Cumberland County

The Census Bureau estimates that 317,222 people lived in Cumberland County on July 1, 2025. That ranks #237 of 3,222 county equivalents nationally and #1 of 16 in Maine. Since the April 1, 2020 estimates base of 303,076, the population has grown by 14,146 (+4.7%), compared with +3.8% for Maine as a whole.

With 836.2 square miles of land, that is 379 people per square mile (146 per km²), placing Cumberland County #427 nationally for density and #1 in Maine. The median county equivalent has 47 people per square mile; the Maine median is 51. Put another way, there are about 1.7 acres of land per resident.

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 Cumberland County

Cumberland County is divided into 28 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 Portland city, with 69,911 residents (22% of the county). The largest by land is Standish town, at 59.1 mi², or 7.1% of the county’s land. Among those with at least 1,000 residents in 2020, Scarborough town grew fastest since then (+11%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Cumberland County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Cumberland County is a central county of the Portland-South Portland, ME Metropolitan Statistical Area. Its 3 county equivalents have 577,635 residents on 2,081.4 square miles of land; Cumberland County accounts for 40.2% of the land and 54.9% of the residents. By combined land it ranks #153 of 393 metropolitan areas, and #103 by population. It belongs to the Portland-Lewiston-South Portland, ME Combined Statistical Area.

ZIP codes

38 ZIP Code Tabulation Areas have land in Cumberland County, and each lies mostly inside the county.

0400304009040110401504017040190402104024040290403204038040390404004050040550405704062040660406904071040740407904084040850409104092040960409704101041020410304105041060410704108041090411004260

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Cumberland County

Cumberland County shares a land border with 4 county equivalents. It has more land than 2 of them. The largest neighbor is Oxford County (2,077 mi²) and the smallest is Sagadahoc County (254 mi²). Together with its neighbors, Cumberland County forms a block of 4,626.3 mi² of land, of which it holds 18.1%.

How big is Cumberland County compared with U.S. states?

Cumberland 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 37 areas the size of Cumberland County.

Another way to picture it: the same land area would fill a square about 28.9 miles (46.5 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 Cumberland County?

Cumberland County has more land than 2,221 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 Cumberland County at #586 nationally by total area, 415 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 31.3%, compared with a national county-equivalent median of 1.2% — 30.1 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 Cumberland County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.