Data / Rankings / Population under 18 / Counties in Pennsylvania

Counties in Pennsylvania by population under 18

Lancaster County had the highest population under 18 of 67 counties in 2024, at 22.5%. Forest County had the lowest, at 8.1%. The median was 19.4% and the figure for Pennsylvania was 19.9%. Source: the U.S. Census Bureau.

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Highest22.5Lancaster County
Lowest8.1Forest County
Median19.467 counties
Pennsylvania19.9History

Map of counties, 2024

Adams County: 18.8 %Allegheny County: 17.9 %Armstrong County: 18.4 %Beaver County: 18.6 %Bedford County: 19.4 %Berks County: 21.5 %Blair County: 19.4 %Bradford County: 21.7 %Bucks County: 19.5 %Butler County: 18.6 %Cambria County: 18.6 %Cameron County: 17.3 %Carbon County: 18.6 %Centre County: 14.4 %Chester County: 21.5 %Clarion County: 19.6 %Clearfield County: 17.7 %Clinton County: 20 %Columbia County: 17.4 %Crawford County: 20.4 %Cumberland County: 20.3 %Dauphin County: 21.4 %Delaware County: 21.7 %Elk County: 18.2 %Erie County: 19.9 %Fayette County: 18.8 %Forest County: 8.1 %Franklin County: 21.8 %Fulton County: 20.1 %Greene County: 18.2 %Huntingdon County: 18 %Indiana County: 18.3 %Jefferson County: 20.5 %Juniata County: 22.1 %Lackawanna County: 19.7 %Lancaster County: 22.5 %Lawrence County: 19.4 %Lebanon County: 21.8 %Lehigh County: 21.6 %Luzerne County: 20 %Lycoming County: 20 %McKean County: 18.9 %Mercer County: 19 %Mifflin County: 22.2 %Monroe County: 19.1 %Montgomery County: 20.5 %Montour County: 19.8 %Northampton County: 18.4 %Northumberland County: 19.8 %Perry County: 21.2 %Philadelphia County: 20 %Pike County: 17.6 %Potter County: 19.2 %Schuylkill County: 19.3 %Snyder County: 20.9 %Somerset County: 17.9 %Sullivan County: 13.7 %Susquehanna County: 19.5 %Tioga County: 19.5 %Union County: 17.4 %Venango County: 19.5 %Warren County: 19.5 %Washington County: 19 %Wayne County: 16.5 %Westmoreland County: 17.8 %Wyoming County: 18.6 %York County: 21.4 %
  • Under 18
  • 18 to 19
  • 19 to 20
  • 20 to 21
  • 21 and over
%, 2024. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2024

Lancaster County: 22.5 %Lancaster County22.5Mifflin County: 22.2 %Mifflin County22.2Juniata County: 22.1 %Juniata County22.1Lebanon County: 21.8 %Lebanon County21.8Franklin County: 21.8 %Franklin County21.8Delaware County: 21.7 %Delaware County21.7Bradford County: 21.7 %Bradford County21.7Lehigh County: 21.6 %Lehigh County21.6Berks County: 21.5 %Berks County21.5Chester County: 21.5 %Chester County21.5York County: 21.4 %York County21.4Dauphin County: 21.4 %Dauphin County21.4Perry County: 21.2 %Perry County21.2Snyder County: 20.9 %Snyder County20.9Jefferson County: 20.5 %Jefferson County20.5Montgomery County: 20.5 %Montgomery County20.5Crawford County: 20.4 %Crawford County20.4Cumberland County: 20.3 %Cumberland County20.3Fulton County: 20.1 %Fulton County20.1Clinton County: 20 %Clinton County20Lycoming County: 20 %Lycoming County20Philadelphia County: 20 %Philadelphia County20Luzerne County: 20 %Luzerne County20Erie County: 19.9 %Erie County19.9Northumberland County: 19.8 %Northumberland County19.8Montour County: 19.8 %Montour County19.8Lackawanna County: 19.7 %Lackawanna County19.7Clarion County: 19.6 %Clarion County19.6Venango County: 19.5 %Venango County19.5Susquehanna County: 19.5 %Susquehanna County19.5Bucks County: 19.5 %Bucks County19.5Warren County: 19.5 %Warren County19.5Tioga County: 19.5 %Tioga County19.5Blair County: 19.4 %Blair County19.4Bedford County: 19.4 %Bedford County19.4Lawrence County: 19.4 %Lawrence County19.4Schuylkill County: 19.3 %Schuylkill County19.3Potter County: 19.2 %Potter County19.2Monroe County: 19.1 %Monroe County19.1Mercer County: 19 %Mercer County19Lancaster County: 22.5 %Lancaster County22.5Mifflin County: 22.2 %Mifflin County22.2Juniata County: 22.1 %Juniata County22.1Lebanon County: 21.8 %Lebanon County21.8Franklin County: 21.8 %Franklin County21.8Delaware County: 21.7 %Delaware County21.7Bradford County: 21.7 %Bradford County21.7Lehigh County: 21.6 %Lehigh County21.6Berks County: 21.5 %Berks County21.5Chester County: 21.5 %Chester County21.5York County: 21.4 %York County21.4Dauphin County: 21.4 %Dauphin County21.4Perry County: 21.2 %Perry County21.2Snyder County: 20.9 %Snyder County20.9Jefferson County: 20.5 %Jefferson County20.5Montgomery County: 20.5 %Montgomery County20.5Crawford County: 20.4 %Crawford County20.4Cumberland County: 20.3 %Cumberland County20.3Fulton County: 20.1 %Fulton County20.1Clinton County: 20 %Clinton County20Lycoming County: 20 %Lycoming County20Philadelphia County: 20 %Philadelphia County20Luzerne County: 20 %Luzerne County20Erie County: 19.9 %Erie County19.9Northumberland County: 19.8 %Northumberland County19.8Montour County: 19.8 %Montour County19.8Lackawanna County: 19.7 %Lackawanna County19.7Clarion County: 19.6 %Clarion County19.6Venango County: 19.5 %Venango County19.5Susquehanna County: 19.5 %Susquehanna County19.5Bucks County: 19.5 %Bucks County19.5Warren County: 19.5 %Warren County19.5Tioga County: 19.5 %Tioga County19.5Blair County: 19.4 %Blair County19.4Bedford County: 19.4 %Bedford County19.4Lawrence County: 19.4 %Lawrence County19.4Schuylkill County: 19.3 %Schuylkill County19.3Potter County: 19.2 %Potter County19.2Monroe County: 19.1 %Monroe County19.1Mercer County: 19 %Mercer County19
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2024 (%)Change on 2023
1Lancaster County22.5-0.2 pts
2Mifflin County22.2-0.1 pts
3Juniata County22.1-0 pts
4Lebanon County21.8-0.2 pts
5Franklin County21.8-0.2 pts
6Delaware County21.7-0.1 pts
7Bradford County21.7-0.1 pts
8Lehigh County21.6-0.2 pts
9Berks County21.5-0.1 pts
10Chester County21.5-0.3 pts
11York County21.4-0.2 pts
12Dauphin County21.4-0.2 pts
13Perry County21.2-0.2 pts
14Snyder County20.9-0.4 pts
15Jefferson County20.5-0 pts
16Montgomery County20.5-0.2 pts
17Crawford County20.4-0.1 pts
18Cumberland County20.3-0.1 pts
19Fulton County20.1-0.4 pts
20Clinton County20-0.3 pts
21Lycoming County20-0.2 pts
22Philadelphia County20-0.2 pts
23Luzerne County200 pts
24Erie County19.9-0.3 pts
25Northumberland County19.8-0.1 pts
26Montour County19.80 pts
27Lackawanna County19.7-0 pts
28Clarion County19.6+0.1 pts
29Venango County19.5-0.2 pts
30Susquehanna County19.5+0.1 pts
31Bucks County19.5-0.2 pts
32Warren County19.50 pts
33Tioga County19.5-0.1 pts
34Blair County19.4-0.2 pts
35Bedford County19.4-0 pts
36Lawrence County19.4-0.1 pts
37Schuylkill County19.3-0 pts
38Potter County19.2-0.3 pts
39Monroe County19.1-0.3 pts
40Mercer County19-0.1 pts
41Washington County19-0.2 pts
42McKean County18.9-0.2 pts
43Fayette County18.8-0.1 pts
44Adams County18.8-0.2 pts
45Cambria County18.6-0.1 pts
46Butler County18.6-0.3 pts
47Wyoming County18.6-0.2 pts
48Beaver County18.6-0.2 pts
49Carbon County18.6-0.2 pts
50Northampton County18.4-0.2 pts
51Armstrong County18.4-0.2 pts
52Indiana County18.3-0.1 pts
53Greene County18.2-0.2 pts
54Elk County18.2-0.1 pts
55Huntingdon County18-0.2 pts
56Somerset County17.9-0.1 pts
57Allegheny County17.9-0.1 pts
58Westmoreland County17.8-0.2 pts
59Clearfield County17.7-0.3 pts
60Pike County17.6-0.3 pts
61Columbia County17.4-0.2 pts
62Union County17.4-0.5 pts
63Cameron County17.3-0.2 pts
64Wayne County16.5-0 pts
65Centre County14.4-0.2 pts
66Sullivan County13.7-0.5 pts
67Forest County8.1-0.5 pts

Other periods

About this ranking

Residents aged 0 to 17 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.

Uses the US age of majority. Not comparable with population_0_14_share, which stops at 14.

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, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (Counties in Pennsylvania by population under 18, 2024) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Pennsylvania by population under 18, 2024. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2024. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Counties in Pennsylvania by population under 18, 2024. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2024.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Pennsylvania by population under 18, 2024 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2024 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_pennsylvania_by_2024,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Pennsylvania by population under 18, 2024}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2024. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Pennsylvania by population under 18, 2024
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2024
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2024.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  -
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Rank Counties in Pennsylvania by population under 18 using official data, and cite the source.
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Questions

Which county has the highest population under 18?

Lancaster County, with 22.5% in 2024, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Forest County, with 8.1% in 2024.

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, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Retrieved 2026-10-12.

Population under 18: other rankings

Counties in Pennsylvania: more rankings