Dorchester County area

Population and density of Dorchester County

The Census Bureau estimates that 178,397 people lived in Dorchester County on July 1, 2025. That ranks #394 of 3,222 county equivalents nationally and #12 of 46 in South Carolina. Since the April 1, 2020 estimates base of 161,330, the population has grown by 17,067 (+10.6%), compared with +8.8% for South Carolina as a whole.

With 568.4 square miles of land, that is 314 people per square mile (121 per km²), placing Dorchester County #493 nationally for density and #9 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 2 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 Dorchester County

7 incorporated places lie at least partly in Dorchester County. Together they are home to 80,928 people (45.4%); the other 97,469 (54.6%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Summerville town, with 44,724 residents in the county (the city extends into 2 other counties). The county seat, St. George town, has 1,868 residents. By land, North Charleston city is the largest at 77.9 mi² across all its counties. Among places with at least 1,000 residents in 2020, North Charleston city grew fastest since then (+13.9%).

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

Metropolitan area

Dorchester 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; Dorchester County accounts for 21.9% of the land and 20.1% of the residents. By combined land it ranks #128 of 393 metropolitan areas, and #67 by population.

ZIP codes

15 ZIP Code Tabulation Areas have land in Dorchester County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

290182941429418294202942629432294372944829456294702947129472294772948329485

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 Dorchester County

Dorchester County shares a land border with 4 county equivalents. Each of them has more land than Dorchester County. The largest neighbor is Orangeburg County (1,106.4 mi²) and the smallest is Charleston County (918.3 mi²). Together with its neighbors, Dorchester County forms a block of 4,753.2 mi² of land, of which it holds 12%.

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

Dorchester County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. South Carolina’s county land could hold about 53 areas the size of Dorchester County.

Another way to picture it: the same land area would fill a square about 23.8 miles (38.4 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 Dorchester County?

Dorchester County has more land than 1,428 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 Dorchester County at #1,920 nationally by total area, 126 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 0.5%, compared with a national county-equivalent median of 1.2% — 0.7 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 Dorchester 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.