Philadelphia County area

Population and density of Philadelphia County

The Census Bureau estimates that 1,574,281 people lived in Philadelphia County on July 1, 2025. That ranks #25 of 3,222 county equivalents nationally and #1 of 67 in Pennsylvania. Since the April 1, 2020 estimates base of 1,603,800, the population has declined by 29,519 (−1.8%), compared with +0.4% for Pennsylvania as a whole.

With 134.3 square miles of land, that is 11,720 people per square mile (4,525 per km²), placing Philadelphia County #8 nationally for density and #1 in Pennsylvania. The median county equivalent has 47 people per square mile; the Pennsylvania median is 137. Put another way, there are about 0.055 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 Philadelphia County

Every resident of Philadelphia County lives within Philadelphia city. The city and the county equivalent cover the same territory, 134.3 square miles of land in the 2026 place Gazetteer, so there are no separate towns or unincorporated areas to list.

Metropolitan area

Philadelphia County is a central county of the Philadelphia-Camden-Wilmington, PA-NJ-DE-MD Metropolitan Statistical Area, in the Philadelphia, PA metropolitan division. Its 11 county equivalents have 6,329,118 residents on 4,603.2 square miles of land; Philadelphia County accounts for 2.9% of the land and 24.9% of the residents. By combined land it ranks #58 of 393 metropolitan areas, and #9 by population. It belongs to the Philadelphia-Reading-Camden, PA-NJ-DE-MD Combined Statistical Area.

ZIP codes

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

19102191031910419106191071910819109191111911219114191151911619118191191912019121191221912319124191251912619127191281912919130191311913219133191341913519136191371913819139191401914119142191431914419145191461914719148191491915019151191521915319154

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 Philadelphia County

Philadelphia County shares a land border with 6 county equivalents, including 3 in New Jersey. Each of them has more land than Philadelphia County. The largest neighbor is Burlington County (799.3 mi²) and the smallest is Delaware County (183.8 mi²). Together with its neighbors, Philadelphia County forms a block of 2,748.2 mi² of land, of which it holds 4.9%.

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

Philadelphia County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 7.7 times as much. Pennsylvania’s county land could hold about 333 areas the size of Philadelphia County.

Another way to picture it: the same land area would fill a square about 11.6 miles (18.7 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 Philadelphia County?

Philadelphia County has more land than 153 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 Philadelphia County at #3,087 nationally by total area, 18 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 5.7%, compared with a national county-equivalent median of 1.2% — 4.5 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 Philadelphia 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.