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 2023, at 22.7%. Forest County had the lowest, at 8.6%. The median was 19.5% and the figure for Pennsylvania was 20%. Source: the U.S. Census Bureau.

Highest22.7Lancaster County
Lowest8.6Forest County
Median19.567 counties
Pennsylvania20History

Top 40 counties, 2023

Lancaster County: 22.7 %Lancaster County22.7Mifflin County: 22.3 %Mifflin County22.3Juniata County: 22.1 %Juniata County22.1Lebanon County: 22 %Lebanon County22Franklin County: 21.9 %Franklin County21.9Delaware County: 21.8 %Delaware County21.8Lehigh County: 21.8 %Lehigh County21.8Chester County: 21.8 %Chester County21.8Bradford County: 21.7 %Bradford County21.7Berks County: 21.6 %Berks County21.6York County: 21.6 %York County21.6Dauphin County: 21.6 %Dauphin County21.6Perry County: 21.4 %Perry County21.4Snyder County: 21.2 %Snyder County21.2Montgomery County: 20.7 %Montgomery County20.7Jefferson County: 20.6 %Jefferson County20.6Crawford County: 20.6 %Crawford County20.6Fulton County: 20.5 %Fulton County20.5Cumberland County: 20.4 %Cumberland County20.4Clinton County: 20.4 %Clinton County20.4Erie County: 20.2 %Erie County20.2Lycoming County: 20.2 %Lycoming County20.2Philadelphia County: 20.2 %Philadelphia County20.2Northumberland County: 20 %Northumberland County20Luzerne County: 19.9 %Luzerne County19.9Montour County: 19.8 %Montour County19.8Lackawanna County: 19.7 %Lackawanna County19.7Venango County: 19.7 %Venango County19.7Bucks County: 19.7 %Bucks County19.7Tioga County: 19.6 %Tioga County19.6Blair County: 19.6 %Blair County19.6Lawrence County: 19.5 %Lawrence County19.5Clarion County: 19.5 %Clarion County19.5Potter County: 19.5 %Potter County19.5Warren County: 19.5 %Warren County19.5Bedford County: 19.5 %Bedford County19.5Susquehanna County: 19.4 %Susquehanna County19.4Monroe County: 19.4 %Monroe County19.4Schuylkill County: 19.3 %Schuylkill County19.3McKean County: 19.1 %McKean County19.1
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2023 (%)Change on 2022
1Lancaster County22.7-0.1 pts
2Mifflin County22.3-0 pts
3Juniata County22.1+0.1 pts
4Lebanon County22-0.1 pts
5Franklin County21.9-0.1 pts
6Delaware County21.8-0.1 pts
7Lehigh County21.8-0.2 pts
8Chester County21.8-0.3 pts
9Bradford County21.7-0 pts
10Berks County21.6-0.2 pts
11York County21.6-0.1 pts
12Dauphin County21.6-0.1 pts
13Perry County21.4-0.2 pts
14Snyder County21.2-0.1 pts
15Montgomery County20.7-0.2 pts
16Jefferson County20.6-0 pts
17Crawford County20.6-0.1 pts
18Fulton County20.5-0.2 pts
19Cumberland County20.40 pts
20Clinton County20.4-0.2 pts
21Erie County20.2-0.2 pts
22Lycoming County20.2-0.2 pts
23Philadelphia County20.2-0.2 pts
24Northumberland County20-0.1 pts
25Luzerne County19.9+0.1 pts
26Montour County19.8-0.4 pts
27Lackawanna County19.70 pts
28Venango County19.7-0.1 pts
29Bucks County19.7-0.2 pts
30Tioga County19.6-0.1 pts
31Blair County19.6-0.1 pts
32Lawrence County19.5-0.2 pts
33Clarion County19.5+0.1 pts
34Potter County19.5-0.3 pts
35Warren County19.5-0 pts
36Bedford County19.5+0.1 pts
37Susquehanna County19.40 pts
38Monroe County19.4-0.4 pts
39Schuylkill County19.3+0.1 pts
40McKean County19.1-0.2 pts
41Washington County19.1-0 pts
42Mercer County19.1-0.2 pts
43Adams County19-0.2 pts
44Butler County18.9-0.2 pts
45Fayette County18.9-0 pts
46Wyoming County18.8-0.3 pts
47Carbon County18.8-0.3 pts
48Beaver County18.7-0.2 pts
49Cambria County18.7-0.1 pts
50Northampton County18.7-0.3 pts
51Armstrong County18.6-0.2 pts
52Greene County18.4-0.2 pts
53Indiana County18.3-0.1 pts
54Elk County18.2-0.2 pts
55Huntingdon County18.2-0.2 pts
56Allegheny County18-0.1 pts
57Somerset County18-0.2 pts
58Pike County18-0.1 pts
59Westmoreland County17.9-0.1 pts
60Clearfield County17.9-0.3 pts
61Union County17.9-0.1 pts
62Columbia County17.6-0 pts
63Cameron County17.5+0.1 pts
64Wayne County16.5-0.2 pts
65Centre County14.6-0.1 pts
66Sullivan County14.2-0.5 pts
67Forest County8.6+0.3 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, 2023) [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, 2023. 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=2023. 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, 2023. 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=2023.

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, 2023 [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=2023 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_pennsylvania_by_2023,
  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, 2023}},
  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=2023. 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, 2023
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=2023
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2023.
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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Questions

Which county has the highest population under 18?

Lancaster County, with 22.7% in 2023, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Forest County, with 8.6% in 2023.

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