Charles County area

Population and density of Charles County

The Census Bureau estimates that 176,593 people lived in Charles County on July 1, 2025. That ranks #399 of 3,222 county equivalents nationally and #10 of 24 in Maryland. Since the April 1, 2020 estimates base of 166,609, the population has grown by 9,984 (+6%), compared with +1.4% for Maryland as a whole.

With 457.8 square miles of land, that is 386 people per square mile (149 per km²), placing Charles County #418 nationally for density and #11 in Maryland. The median county equivalent has 47 people per square mile; the Maryland median is 335. 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 Charles County

3 incorporated places lie at least partly in Charles County. Together they are home to 16,362 people (9.3%); the other 160,231 (90.7%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is La Plata town, with 12,137 residents in the county. Among places with at least 1,000 residents in 2020, La Plata town grew fastest since then (+19.2%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Charles County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Charles County is an outlying county of the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area, in the Washington, DC-MD metropolitan division. Its 23 county equivalents have 6,465,724 residents on 6,033.7 square miles of land; Charles County accounts for 7.6% of the land and 2.7% of the residents. By combined land it ranks #35 of 393 metropolitan areas, and #7 by population. It belongs to the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area.

ZIP codes

25 ZIP Code Tabulation Areas have land in Charles County; 22 of them have most of their land inside the county, and the others mainly cover neighboring areas.

20601206022060320607206112061220613206162061720622206252063220637206402064520646206582065920661206622066420675206772069320695

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 Charles County

Charles County shares a land border with 4 county equivalents, including 1 in Virginia. It has more land than 3 of them. The largest neighbor is Prince George's County (482.6 mi²) and the smallest is Calvert County (213.2 mi²). Together with its neighbors, Charles County forms a block of 1,903.2 mi² of land, of which it holds 24.1%.

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

Charles County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.3 times as much. Maryland’s county land could hold about 21 areas the size of Charles County.

Another way to picture it: the same land area would fill a square about 21.4 miles (34.4 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 Charles County?

Charles County has more land than 984 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 Charles County at #1,599 nationally by total area, 639 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 28.8%, compared with a national county-equivalent median of 1.2% — 27.6 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 Charles 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.