Counties in Pennsylvania by population under 18

Lancaster County had the highest population under 18 of 67 counties in 2019, at 23.2%. Forest County had the lowest, at 9.3%. The median was 19.9% and the figure for Pennsylvania was 20.5%. Source: the U.S. Census Bureau.

Highest23.2Lancaster County
Lowest9.3Forest County
Median19.967 counties
Pennsylvania20.5History

Top 40 counties, 2019

Lancaster County: 23.2 %Lancaster County23.2Chester County: 22.9 %Chester County22.9Franklin County: 22.5 %Franklin County22.5Lebanon County: 22.4 %Lebanon County22.4Berks County: 22.3 %Berks County22.3Lehigh County: 22.2 %Lehigh County22.2Juniata County: 22.1 %Juniata County22.1Delaware County: 22 %Delaware County22York County: 22 %York County22Mifflin County: 21.8 %Mifflin County21.8Dauphin County: 21.8 %Dauphin County21.8Perry County: 21.7 %Perry County21.7Bradford County: 21.6 %Bradford County21.6Snyder County: 21.5 %Snyder County21.5Montgomery County: 21.4 %Montgomery County21.4Erie County: 21 %Erie County21Clinton County: 20.9 %Clinton County20.9Jefferson County: 20.8 %Jefferson County20.8Fulton County: 20.8 %Fulton County20.8Montour County: 20.7 %Montour County20.7Crawford County: 20.6 %Crawford County20.6Philadelphia County: 20.6 %Philadelphia County20.6Lycoming County: 20.5 %Lycoming County20.5Bucks County: 20.4 %Bucks County20.4Cumberland County: 20.3 %Cumberland County20.3Tioga County: 20.3 %Tioga County20.3Monroe County: 20.3 %Monroe County20.3Adams County: 20.1 %Adams County20.1Northumberland County: 20.1 %Northumberland County20.1Venango County: 20.1 %Venango County20.1McKean County: 20.1 %McKean County20.1Potter County: 20 %Potter County20Butler County: 20 %Butler County20Blair County: 19.9 %Blair County19.9Lawrence County: 19.7 %Lawrence County19.7Northampton County: 19.7 %Northampton County19.7Lackawanna County: 19.7 %Lackawanna County19.7Mercer County: 19.6 %Mercer County19.6Bedford County: 19.5 %Bedford County19.5Clarion County: 19.4 %Clarion County19.4
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2019 (%)Change on 2018
1Lancaster County23.2-0.2 pts
2Chester County22.9-0.1 pts
3Franklin County22.5-0.2 pts
4Lebanon County22.4-0.2 pts
5Berks County22.3-0.2 pts
6Lehigh County22.2-0.1 pts
7Juniata County22.1-0.2 pts
8Delaware County22-0.1 pts
9York County22-0.1 pts
10Mifflin County21.8-0.1 pts
11Dauphin County21.8-0.1 pts
12Perry County21.7-0.1 pts
13Bradford County21.6-0.1 pts
14Snyder County21.5-0.1 pts
15Montgomery County21.4-0.1 pts
16Erie County21-0.3 pts
17Clinton County20.9+0.1 pts
18Jefferson County20.8-0.1 pts
19Fulton County20.8+0.1 pts
20Montour County20.7-0.1 pts
21Crawford County20.6-0.3 pts
22Philadelphia County20.6-0.3 pts
23Lycoming County20.5-0 pts
24Bucks County20.4-0.2 pts
25Cumberland County20.30 pts
26Tioga County20.3-0.1 pts
27Monroe County20.3-0.1 pts
28Adams County20.1-0.3 pts
29Northumberland County20.1+0.1 pts
30Venango County20.1-0.1 pts
31McKean County20.1-0 pts
32Potter County20-0.4 pts
33Butler County20-0.2 pts
34Blair County19.9-0.1 pts
35Lawrence County19.7-0 pts
36Northampton County19.7-0.2 pts
37Lackawanna County19.7-0.1 pts
38Mercer County19.6-0.1 pts
39Bedford County19.5-0.2 pts
40Clarion County19.4-0 pts
41Luzerne County19.4-0 pts
42Susquehanna County19.4+0.1 pts
43Carbon County19.3-0.1 pts
44Warren County19.3-0.1 pts
45Washington County19.2-0 pts
46Wyoming County19.2-0.3 pts
47Beaver County19.1-0.1 pts
48Schuylkill County19-0.2 pts
49Pike County18.9-0.2 pts
50Cambria County18.9-0.1 pts
51Armstrong County18.8-0.2 pts
52Fayette County18.8-0.1 pts
53Greene County18.7-0.1 pts
54Elk County18.7-0.3 pts
55Union County18.7+0.1 pts
56Indiana County18.60 pts
57Allegheny County18.5-0.1 pts
58Westmoreland County18.4-0.1 pts
59Huntingdon County18.2-0 pts
60Clearfield County18.2-0.1 pts
61Columbia County18.1-0.1 pts
62Somerset County18-0 pts
63Cameron County17.8+0.1 pts
64Sullivan County16.8+0.2 pts
65Wayne County16.8-0.2 pts
66Centre County15.3-0 pts
67Forest County9.3+0.4 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, 2019) [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, 2019. 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=2019. 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, 2019. 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=2019.

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, 2019 [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=2019 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_pennsylvania_by_2019,
  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, 2019}},
  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=2019. 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, 2019
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=2019
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2019.
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 23.2% in 2019, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Forest County, with 9.3% in 2019.

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