Charleston County area

Population and density of Charleston County

The Census Bureau estimates that 436,200 people lived in Charleston County on July 1, 2025. That ranks #172 of 3,222 county equivalents nationally and #2 of 46 in South Carolina. Since the April 1, 2020 estimates base of 408,522, the population has grown by 27,678 (+6.8%), compared with +8.8% for South Carolina as a whole.

With 918.3 square miles of land, that is 475 people per square mile (183 per km²), placing Charleston County #351 nationally for density and #3 in South Carolina. The median county equivalent has 47 people per square mile; the South Carolina median is 78. Put another way, there are about 1.3 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 Charleston County

17 incorporated places lie at least partly in Charleston County. Together they are home to 376,621 people (86.3%); the other 59,579 (13.7%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Charleston city, with 142,732 residents in the county (the city extends into 1 other county). Among places with at least 1,000 residents in 2020, North Charleston city grew fastest since then (+12%).

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

Metropolitan area

Charleston County is a central county of the Charleston-North Charleston, SC Metropolitan Statistical Area. Its 3 county equivalents have 889,263 residents on 2,590.3 square miles of land; Charleston County accounts for 35.5% of the land and 49.1% of the residents. By combined land it ranks #128 of 393 metropolitan areas, and #67 by population.

ZIP codes

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

29401294032940429405294062940729409294102941229414294182942029424294252942629429294382943929449294502945129455294562945829464294662947029482294832948529487

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 Charleston County

Charleston County shares a land border with 4 county equivalents. It has more land than 2 of them. The largest neighbor is Berkeley County (1,103.6 mi²) and the smallest is Dorchester County (568.4 mi²). Together with its neighbors, Charleston County forms a block of 4,460.4 mi² of land, of which it holds 20.6%.

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

Charleston County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.1 times as much. South Carolina’s county land could hold about 33 areas the size of Charleston County.

Another way to picture it: the same land area would fill a square about 30.3 miles (48.8 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 Charleston County?

Charleston County has more land than 2,421 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 Charleston County at #502 nationally by total area, 299 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 32.8%, compared with a national county-equivalent median of 1.2% — 31.7 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 Charleston 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.