• county
  • FIPS 42003
  • Largest town: Pittsburgh

Allegheny County, Pennsylvania

Allegheny County had 1,231,814 residents in the Census Vintage 2024 estimate, on 730.0 square miles of land. It ranks 2nd of 67 in Pennsylvania by population and 29th by land area.

Population
1,231,814
#2 of 67 in Pennsylvania · #38 in US
Area
730.0 sq mi
#29 of 67 in Pennsylvania · #1,215 in US
Density
1,688 / sq mi
#4 of 67 in Pennsylvania · #89 in US
Median household income
$76,488
#14 of 67 in Pennsylvania · #604 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Allegheny County within Pennsylvania. Pin: Harrisburg.

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Allegheny County population, land area and income

Allegheny County had 1,231,814 residents in the Census Vintage 2024 estimate, on 730.0 square miles of land. It ranks 2nd of 67 in Pennsylvania by population and 29th by land area. That works out to 1,687.5 people per square mile, 17.5 times the US average of 96.3, and in the top tenth nationally.

The median county-equivalent in Pennsylvania has 82,953 residents, so Allegheny County is 14.8 times that size.

Its SAIPE 2023 median household income of $76,488 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

1,231,814

3144th1st

38th of 3,144 (US)

Land area

730 sq mi

3144th1st

1215th of 3,144 (US)

Density

1,687.5 / sq mi

3144th1st

89th of 3,144 (US)

Median household income

$76,488

3143rd1st

604th of 3,143 (US)

Rank within Pennsylvania (67)

Population

1,231,814

67th1st

2nd of 67 (PA)

Land area

730 sq mi

67th1st

29th of 67 (PA)

Density

1,687.5 / sq mi

67th1st

4th of 67 (PA)

Median household income

$76,488

67th1st

14th of 67 (PA)

How Allegheny County's population changed since 2020

Allegheny County lost 17,857 residents between the July 2020 and July 2024 estimates, a drop of 1.4%. That ranks 46th of 67 in Pennsylvania for growth. The median Pennsylvania county changed by -0.5%, and the state as a whole by +0.6%.

Since the April 2020 estimates base, Allegheny County recorded 50,979 births and 61,749 deaths, a natural change of -10,770. Net international migration added +20,797 and net domestic migration, people moving to or from other US counties, came to -29,871. The largest single component was domestic migration, which removed 29,871 people.

1.25M20201.25M20211.23M20221.23M20231.23M2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
50,979
Deaths
61,749
Net international migration
+20,797
Net domestic migration
-29,871
Change, July 2023 to July 2024
+1,676

Where Allegheny County is

The Census internal point of Allegheny County is at 40.469800, -79.980500. It sits in UTM zone 17N. The map shades Pennsylvania's 67 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Allegheny County outlined. Dots are towns of 1,000+ people with residents in it.

Adams County: +4.0%Potter County: -2.4%Sullivan County: +1.6%Bucks County: +0.6%Carbon County: +1.5%McKean County: -2.3%Montour County: -0.1%Fulton County: -0.9%Columbia County: +2.0%Cameron County: -4.1%Elk County: -2.6%Bradford County: -0.4%Bedford County: +0.1%York County: +3.2%Monroe County: -1.1%Forest County: -5.2%Berks County: +2.4%Cambria County: -2.3%Franklin County: +2.1%Snyder County: -0.3%Somerset County: -2.5%Clarion County: -0.9%Indiana County: -0.2%Lackawanna County: +0.6%Wyoming County: -1.0%Lawrence County: -2.0%Mercer County: -2.2%Lehigh County: +3.0%Northampton County: +3.3%Cumberland County: +5.9%Fayette County: -3.6%Jefferson County: -2.5%Centre County: +1.2%Lebanon County: +1.4%Union County: -1.2%Clinton County: +1.3%Chester County: +4.8%Montgomery County: +2.6%Wayne County: +0.5%Pike County: +6.5%Susquehanna County: -0.6%Allegheny County: -1.4%Clearfield County: -2.9%Butler County: +2.7%Beaver County: -1.4%Crawford County: -2.1%Washington County: +0.5%Venango County: -1.7%Warren County: -3.0%Blair County: -2.0%Huntingdon County: -1.6%Lancaster County: +1.9%Luzerne County: +1.9%Westmoreland County: -1.0%Juniata County: -0.4%Armstrong County: -2.7%Tioga County: -0.8%Delaware County: +1.4%Northumberland County: -1.7%Mifflin County: -0.5%Lycoming County: -0.8%Perry County: +2.1%Philadelphia County: -1.7%Schuylkill County: +1.1%Dauphin County: +2.2%Greene County: -5.3%Erie County: -1.1%
Change 2020 to 2024
  1. < -2.2%
  2. < -1.0%
  3. < +0.1%
  4. < +1.9%
  5. ≥ +1.9%
no data

Orange pin: Allegheny County internal point. Dark pin: Harrisburg.

Internal point

Decimal
40.469800, -79.980500
DMS
40°28'11.28"N 79°58'49.80"W
UTM
17N 586425.6E 4480401.6N
Geohash
dppn5zrcx
Plus code
87G2F299+WR

Towns in Allegheny County

75 incorporated places of 1,000+ people have residents in Allegheny County, 749,861 people together, or 61% of the county. Each figure counts only the part of the town inside Allegheny County; towns marked "part" extend into another county. The largest is Pittsburgh with 307,668.

  1. 01Pittsburgh307,668
  2. 02Bethel Park32,376
  3. 03Monroeville27,966
  4. 04Plum26,420
  5. 05Baldwin20,712
  6. 06West Mifflin18,902
  7. 07McKeesport17,119
  8. 08Franklin Park15,079
  9. 09Whitehall14,678
  10. 10Wilkinsburg13,800
  11. 11Jefferson Hills12,291
  12. 12Munhall10,371
  13. 13Brentwood9,704
  14. 14Pleasant Hills8,318
  15. 15Swissvale8,280
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Allegheny County

The Census 2024 county adjacency file lists 4 neighbors for Allegheny County. The most populous is Westmoreland County, PA, with 350,935 residents. Distances run between Census internal points in a straight line.

Distance to Harrisburg and the nearest big city

Harrisburg is 163.6 miles E of Allegheny County's internal point in a straight line. The nearest place of 100,000 or more is Pittsburgh, PA (population 307,668), 2.1 miles away.

Allegheny County FIPS code

The FIPS code of Allegheny County is 42003: state code 42 for Pennsylvania plus county code 003. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $76,488.

Questions people ask

What is the population of Allegheny County, Pennsylvania?

The Census Vintage 2024 estimate for July 1, 2024 is 1,231,814. That is down 17,857 people (1.4%) from the July 2020 estimate of 1,249,671.

What is the FIPS code of Allegheny County?

42003. The first two digits (42) are Pennsylvania; the last three (003) identify the county.

What is the largest town in Allegheny County?

Pittsburgh, with 307,668 residents inside Allegheny County in 2024.

Which counties border Allegheny County?

4 county-equivalents border it in the Census 2024 adjacency file: Westmoreland County, PA; Washington County, PA; Butler County, PA; Beaver County, PA.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.