County facts · Population · October 24, 2026
Pennsylvania Population by County, 2025 Census Estimates
Pennsylvania population by county: July 2025 Census estimates for all 67 counties, change since 2020, density, and a link to each official parcel map.
Looking for Pennsylvania population by county? The Census Bureau estimates that Pennsylvania had 13,059,432 residents on July 1, 2025, spread across 67 counties. Philadelphia County is the most populous, with 1,574,281 people (12% of the state), and Cameron County is the least populous, with 4,211.
The table below lists every county with its 2025 estimate, its April 2020 starting point, the change, people per square mile, and a link to its official parcel viewer.
Pennsylvania population at a glance
- Counties: 67
- Statewide, July 1, 2025: 13,059,432 (April 1, 2020 estimates base: 13,002,753; change +56,679, +0.4%)
- Most populous: Philadelphia County (1,574,281); least populous: Cameron County (4,211)
- Median county: about 82,878 residents (half of the counties are smaller)
- The 5 largest counties hold 38% of all Pennsylvania residents
- Counties with 1,000,000+ residents: 2 · 100,000+: 31 · under 10,000: 3
- Statewide density: about 292 people per square mile of land
Pennsylvania population by county, July 2025 (all 67)
Percent change runs from the April 1, 2020 estimates base to July 1, 2025. People per square mile is the July 2025 estimate divided by the county's land area in the Census Bureau's 2020 Gazetteer file, so lakes and bays are left out.
How Pennsylvania's population is spread out
Grouping the counties by size shows how concentrated the state is:
| Residents (July 2025) | Counties | Total residents | Share of state |
|---|---|---|---|
| 1,000,000 or more | 2 | 2,799,316 | 21% |
| 250,000 to 999,999 | 14 | 6,366,649 | 49% |
| 100,000 to 249,999 | 15 | 2,269,765 | 17% |
| 25,000 to 99,999 | 29 | 1,535,370 | 12% |
| 10,000 to 24,999 | 4 | 71,651 | 1% |
| Under 10,000 | 3 | 16,681 | 0% |
16 counties with at least 250,000 residents hold 70% of the state's population.
Most and least densely populated
The most crowded counties by people per square mile of land:
- Philadelphia County: 11,717 per sq mi (1,574,281 people on 134 sq mi)
- Delaware County: 3,160 per sq mi (580,937 people on 184 sq mi)
- Montgomery County: 1,817 per sq mi (877,643 people on 483 sq mi)
- Allegheny County: 1,678 per sq mi (1,225,035 people on 730 sq mi)
- Lehigh County: 1,113 per sq mi (384,383 people on 345 sq mi)
The most thinly settled:
- Cameron County: 11 per sq mi (4,211 people on 396 sq mi)
- Sullivan County: 13 per sq mi (5,856 people on 450 sq mi)
- Potter County: 15 per sq mi (15,897 people on 1,081 sq mi)
- Forest County: 15 per sq mi (6,614 people on 427 sq mi)
- Fulton County: 33 per sq mi (14,483 people on 438 sq mi)
About these numbers
- They are estimates. Between censuses the Census Bureau's Population Estimates Program updates county totals each year from births, deaths and migration records. The next full count is the 2030 census.
- The base is April 1, 2020. The estimates start from an April 1, 2020 "estimates base" built from the 2020 census, which is why it is slightly different from the published census count.
- Each new release revises the past. A newer vintage can change earlier years as well, so compare numbers from the same release, as this page does.
- Statewide total. The counties add up exactly to the statewide figure of 13,059,432 in the same file.
Using population numbers in a land search
- Big counties, busy offices. In the most populous counties, parcel maps and deed records are usually online and searchable, but recording and permit offices are busier. Allow for that if you are on a deadline.
- Small counties, fewer sales. In counties with only a few thousand people, land changes hands less often, so there are fewer recent sales to compare a price with. The county assessor's sales records are the best source.
- Density hints at lot size. A low people-per-square-mile figure usually means farms, ranches and timber tracts; a high one means subdivided lots. The parcel viewer shows the actual parcel lines.
- Check the official map. Use the parcel viewer link in the table for boundaries, parcel numbers and owner names, then confirm anything important with the county's recorder or assessor.
Related guides
- Fastest growing counties in Pennsylvania
- Largest counties in Pennsylvania
- Pennsylvania county GIS websites by viewer
- Pennsylvania plat maps
- Pennsylvania landowner maps for hunting
- Most populous counties in the US
- Where people are moving in the US
More: All Pennsylvania counties on Platbookmapper
Sources
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2025 (April 1, 2020 estimates base and July 1, 2020–2025 estimates, with components of change). Statewide totals are the sum of the counties and match the file's state row.
- U.S. Census Bureau Gazetteer files, 2020 county land and water area (for people per square mile).
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 24, 2026) for each official parcel viewer.