Data / Rankings / Population density / Counties in Pennsylvania

Counties in Pennsylvania by population density

Philadelphia County had the highest population density of 67 counties in 2021, at 4,570.9 inhabitants per km². Cameron County had the lowest, at 4.4 inhabitants per km². The median was 53.6 inhabitants per km² and the figure for Pennsylvania was 112.3 inhabitants per km². Source: the U.S. Census Bureau.

Highest4,570.9Philadelphia County
Lowest4.4Cameron County
Median53.667 counties
Pennsylvania112.3History

Top 40 counties, 2021

CSVChart (SVG)

Philadelphia CountyPhiladelphia County: 4,570.9 inhabitants per km²4,570.9Delaware CountyDelaware County: 1,212.4 inhabitants per km²1,212.4Montgomery CountyMontgomery County: 691 inhabitants per km²691Allegheny CountyAllegheny County: 658.7 inhabitants per km²658.7Lehigh CountyLehigh County: 420.2 inhabitants per km²420.2Bucks CountyBucks County: 413.8 inhabitants per km²413.8Northampton CountyNorthampton County: 332.3 inhabitants per km²332.3Chester CountyChester County: 278.4 inhabitants per km²278.4Lancaster CountyLancaster County: 227.6 inhabitants per km²227.6Dauphin CountyDauphin County: 212.1 inhabitants per km²212.1York CountyYork County: 196.1 inhabitants per km²196.1Berks CountyBerks County: 193.7 inhabitants per km²193.7Cumberland CountyCumberland County: 188 inhabitants per km²188Lackawanna CountyLackawanna County: 181.8 inhabitants per km²181.8Lebanon CountyLebanon County: 153.4 inhabitants per km²153.4Beaver CountyBeaver County: 148.3 inhabitants per km²148.3Luzerne CountyLuzerne County: 141.4 inhabitants per km²141.4Westmoreland CountyWestmoreland County: 132.9 inhabitants per km²132.9Erie CountyErie County: 130.2 inhabitants per km²130.2Monroe CountyMonroe County: 107.1 inhabitants per km²107.1Butler CountyButler County: 96.2 inhabitants per km²96.2Washington CountyWashington County: 94.7 inhabitants per km²94.7Lawrence CountyLawrence County: 92.4 inhabitants per km²92.4Blair CountyBlair County: 89.8 inhabitants per km²89.8Adams CountyAdams County: 78.7 inhabitants per km²78.7Franklin CountyFranklin County: 78.3 inhabitants per km²78.3Northumberland CountyNorthumberland County: 76.8 inhabitants per km²76.8Cambria CountyCambria County: 74.2 inhabitants per km²74.2Schuylkill CountySchuylkill County: 71 inhabitants per km²71Carbon CountyCarbon County: 66.4 inhabitants per km²66.4Mercer CountyMercer County: 63.2 inhabitants per km²63.2Fayette CountyFayette County: 62.1 inhabitants per km²62.1Centre CountyCentre County: 55.1 inhabitants per km²55.1Montour CountyMontour County: 53.6 inhabitants per km²53.6Columbia CountyColumbia County: 51.9 inhabitants per km²51.9Union CountyUnion County: 51.9 inhabitants per km²51.9Snyder CountySnyder County: 46.7 inhabitants per km²46.7Mifflin CountyMifflin County: 43.4 inhabitants per km²43.4Pike CountyPike County: 42.6 inhabitants per km²42.6Indiana CountyIndiana County: 38.8 inhabitants per km²38.8
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2021
inhabitants per km²		Change on 2020
1Philadelphia County4,570.9-0.7%
2Delaware County1,212.4+0.1%
3Montgomery County691+0.9%
4Allegheny County658.7-0.3%
5Lehigh County420.2+0.4%
6Bucks County413.8+0.2%
7Northampton County332.3+1.7%
8Chester County278.4+1.2%
9Lancaster County227.6+0.7%
10Dauphin County212.1+0.6%
11York County196.1+0.6%
12Berks County193.7+0.2%
13Cumberland County188+2%
14Lackawanna County181.8+0.3%
15Lebanon County153.4+0.4%
16Beaver County148.3-0.5%
17Luzerne County141.4+0.2%
18Westmoreland County132.9-0.2%
19Erie County130.2-0.5%
20Monroe County107.1+0.3%
21Butler County96.2+1.4%
22Washington County94.7+0.3%
23Lawrence County92.4-0.5%
24Blair County89.8-0.4%
25Adams County78.7+1.8%
26Franklin County78.3+0.4%
27Northumberland County76.8-0.6%
28Cambria County74.2-0.7%
29Schuylkill County71+0.1%
30Carbon County66.4+1.2%
31Mercer County63.2-0.5%
32Fayette County62.1-1.1%
33Centre County55.1-0%
34Montour County53.6-0.2%
35Columbia County51.9+0.5%
36Union County51.9-0.4%
37Snyder County46.7-0%
38Mifflin County43.4+0.1%
39Pike County42.6+2.5%
40Indiana County38.8-0.1%
41Armstrong County38.6-0.3%
42Lycoming County35.7-0.5%
43Perry County32.2+0.3%
44Crawford County31.7-0.7%
45Venango County28.7-0.6%
46Wayne County27.2+0.1%
47Clearfield County26.4-2.6%
48Somerset County26.2-1.4%
49Jefferson County26.1-0.8%
50Wyoming County25.4+0.3%
51Clarion County24.2+1.1%
52Greene County23.7-1.6%
53Juniata County23-0.6%
54Bradford County20.3+0.3%
55Huntingdon County19.4-0.2%
56Bedford County18.1-0.1%
57Susquehanna County18+0.3%
58Warren County16.7-0.9%
59Clinton County16.5+1.7%
60McKean County15.9-0.1%
61Elk County14.4-0.5%
62Tioga County14.1+0.7%
63Fulton County12.9-0.1%
64Forest County6.2-1%
65Potter County5.8-0.4%
66Sullivan County5+0.7%
67Cameron County4.4-1.5%

Other periods

About this ranking

Resident population divided by land area in km². World Bank figures use mid-year population and land area excluding inland water.

United States: Census Bureau population estimates for 1 July divided by land area (water excluded) from the latest Census Gazetteer files. US tables often give people per square mile; multiply persons per km² by 2.59 to compare.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-09.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Pennsylvania by population density using official data, and cite the source.
rank_places {"indicator":"population_density","level":"province","within":"Pennsylvania","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_density&level=province&within=Pennsylvania&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest population density?

Philadelphia County, with 4,570.9 inhabitants per km² in 2021, according to the U.S. Census Bureau.

Which county has the lowest population density?

Cameron County, with 4.4 inhabitants per km² in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². Retrieved 2026-10-09.

Population density: other rankings

Counties in Pennsylvania: more rankings