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 2015, at 23.8%. Forest County had the lowest, at 9.5%. The median was 20.3% and the figure for Pennsylvania was 21%. Source: the U.S. Census Bureau.

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Highest23.8Lancaster County
Lowest9.5Forest County
Median20.367 counties
Pennsylvania21History

Map of counties, 2015

Adams County: 20.9 %Allegheny County: 18.9 %Armstrong County: 19.4 %Beaver County: 19.5 %Bedford County: 20.4 %Berks County: 22.8 %Blair County: 20.4 %Bradford County: 22.1 %Bucks County: 21.2 %Butler County: 20.8 %Cambria County: 19.3 %Cameron County: 17.8 %Carbon County: 19.8 %Centre County: 15.4 %Chester County: 23.6 %Clarion County: 19.4 %Clearfield County: 18.7 %Clinton County: 20.8 %Columbia County: 18.1 %Crawford County: 21.3 %Cumberland County: 20.3 %Dauphin County: 22.1 %Delaware County: 22.4 %Elk County: 19.6 %Erie County: 21.7 %Fayette County: 19.3 %Forest County: 9.5 %Franklin County: 23.1 %Fulton County: 20.9 %Greene County: 19.1 %Huntingdon County: 18.9 %Indiana County: 18.5 %Jefferson County: 21.1 %Juniata County: 22.6 %Lackawanna County: 19.8 %Lancaster County: 23.8 %Lawrence County: 19.9 %Lebanon County: 23 %Lehigh County: 22.6 %Luzerne County: 19.4 %Lycoming County: 20.6 %McKean County: 20.3 %Mercer County: 20.3 %Mifflin County: 22.4 %Monroe County: 20.8 %Montgomery County: 21.9 %Montour County: 20.5 %Northampton County: 20.3 %Northumberland County: 20.1 %Perry County: 22.1 %Philadelphia County: 21.6 %Pike County: 19.6 %Potter County: 21.2 %Schuylkill County: 19.4 %Snyder County: 21.7 %Somerset County: 18.3 %Sullivan County: 16 %Susquehanna County: 19.6 %Tioga County: 20.2 %Union County: 18.3 %Venango County: 20.6 %Warren County: 19.6 %Washington County: 19.7 %Wayne County: 17.5 %Westmoreland County: 18.9 %Wyoming County: 20.3 %York County: 22.4 %
  • Under 19
  • 19 to 20
  • 20 to 21
  • 21 to 22
  • 22 and over
%, 2015. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2015

Lancaster County: 23.8 %Lancaster County23.8Chester County: 23.6 %Chester County23.6Franklin County: 23.1 %Franklin County23.1Lebanon County: 23 %Lebanon County23Berks County: 22.8 %Berks County22.8Lehigh County: 22.6 %Lehigh County22.6Juniata County: 22.6 %Juniata County22.6Mifflin County: 22.4 %Mifflin County22.4York County: 22.4 %York County22.4Delaware County: 22.4 %Delaware County22.4Perry County: 22.1 %Perry County22.1Bradford County: 22.1 %Bradford County22.1Dauphin County: 22.1 %Dauphin County22.1Montgomery County: 21.9 %Montgomery County21.9Erie County: 21.7 %Erie County21.7Snyder County: 21.7 %Snyder County21.7Philadelphia County: 21.6 %Philadelphia County21.6Crawford County: 21.3 %Crawford County21.3Potter County: 21.2 %Potter County21.2Bucks County: 21.2 %Bucks County21.2Jefferson County: 21.1 %Jefferson County21.1Fulton County: 20.9 %Fulton County20.9Adams County: 20.9 %Adams County20.9Butler County: 20.8 %Butler County20.8Clinton County: 20.8 %Clinton County20.8Monroe County: 20.8 %Monroe County20.8Venango County: 20.6 %Venango County20.6Lycoming County: 20.6 %Lycoming County20.6Montour County: 20.5 %Montour County20.5Bedford County: 20.4 %Bedford County20.4Blair County: 20.4 %Blair County20.4McKean County: 20.3 %McKean County20.3Cumberland County: 20.3 %Cumberland County20.3Northampton County: 20.3 %Northampton County20.3Wyoming County: 20.3 %Wyoming County20.3Mercer County: 20.3 %Mercer County20.3Tioga County: 20.2 %Tioga County20.2Northumberland County: 20.1 %Northumberland County20.1Lawrence County: 19.9 %Lawrence County19.9Lackawanna County: 19.8 %Lackawanna County19.8Lancaster County: 23.8 %Lancaster County23.8Chester County: 23.6 %Chester County23.6Franklin County: 23.1 %Franklin County23.1Lebanon County: 23 %Lebanon County23Berks County: 22.8 %Berks County22.8Lehigh County: 22.6 %Lehigh County22.6Juniata County: 22.6 %Juniata County22.6Mifflin County: 22.4 %Mifflin County22.4York County: 22.4 %York County22.4Delaware County: 22.4 %Delaware County22.4Perry County: 22.1 %Perry County22.1Bradford County: 22.1 %Bradford County22.1Dauphin County: 22.1 %Dauphin County22.1Montgomery County: 21.9 %Montgomery County21.9Erie County: 21.7 %Erie County21.7Snyder County: 21.7 %Snyder County21.7Philadelphia County: 21.6 %Philadelphia County21.6Crawford County: 21.3 %Crawford County21.3Potter County: 21.2 %Potter County21.2Bucks County: 21.2 %Bucks County21.2Jefferson County: 21.1 %Jefferson County21.1Fulton County: 20.9 %Fulton County20.9Adams County: 20.9 %Adams County20.9Butler County: 20.8 %Butler County20.8Clinton County: 20.8 %Clinton County20.8Monroe County: 20.8 %Monroe County20.8Venango County: 20.6 %Venango County20.6Lycoming County: 20.6 %Lycoming County20.6Montour County: 20.5 %Montour County20.5Bedford County: 20.4 %Bedford County20.4Blair County: 20.4 %Blair County20.4McKean County: 20.3 %McKean County20.3Cumberland County: 20.3 %Cumberland County20.3Northampton County: 20.3 %Northampton County20.3Wyoming County: 20.3 %Wyoming County20.3Mercer County: 20.3 %Mercer County20.3Tioga County: 20.2 %Tioga County20.2Northumberland County: 20.1 %Northumberland County20.1Lawrence County: 19.9 %Lawrence County19.9Lackawanna County: 19.8 %Lackawanna County19.8
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2015 (%)Change on 2014
1Lancaster County23.8-0.2 pts
2Chester County23.6-0.1 pts
3Franklin County23.1-0.2 pts
4Lebanon County23-0 pts
5Berks County22.8-0.1 pts
6Lehigh County22.6-0.1 pts
7Juniata County22.6-0.2 pts
8Mifflin County22.4-0.1 pts
9York County22.4-0.1 pts
10Delaware County22.4-0.1 pts
11Perry County22.10 pts
12Bradford County22.1-0.1 pts
13Dauphin County22.1-0.1 pts
14Montgomery County21.9-0.2 pts
15Erie County21.7-0.2 pts
16Snyder County21.7-0 pts
17Philadelphia County21.6-0.1 pts
18Crawford County21.3-0.1 pts
19Potter County21.2-0.1 pts
20Bucks County21.2-0.3 pts
21Jefferson County21.1-0 pts
22Fulton County20.9-0.4 pts
23Adams County20.9-0.1 pts
24Butler County20.8-0.2 pts
25Clinton County20.80 pts
26Monroe County20.8-0.6 pts
27Venango County20.6-0 pts
28Lycoming County20.6-0.2 pts
29Montour County20.50 pts
30Bedford County20.4-0.3 pts
31Blair County20.4-0 pts
32McKean County20.3-0.2 pts
33Cumberland County20.3-0 pts
34Northampton County20.3-0.2 pts
35Wyoming County20.3-0.3 pts
36Mercer County20.3-0.2 pts
37Tioga County20.2+0.3 pts
38Northumberland County20.1-0 pts
39Lawrence County19.9-0.1 pts
40Lackawanna County19.80 pts
41Carbon County19.8-0.1 pts
42Washington County19.7-0.1 pts
43Elk County19.6-0.2 pts
44Pike County19.6-0.4 pts
45Warren County19.6-0.1 pts
46Susquehanna County19.6-0.2 pts
47Beaver County19.5-0.1 pts
48Schuylkill County19.4-0.1 pts
49Armstrong County19.4-0.3 pts
50Clarion County19.4+0.1 pts
51Luzerne County19.4-0.1 pts
52Cambria County19.30 pts
53Fayette County19.3-0.1 pts
54Greene County19.1-0 pts
55Westmoreland County18.9-0.1 pts
56Huntingdon County18.9-0.1 pts
57Allegheny County18.9-0.1 pts
58Clearfield County18.7-0.1 pts
59Indiana County18.5-0 pts
60Somerset County18.3-0.2 pts
61Union County18.3-0.2 pts
62Columbia County18.1-0 pts
63Cameron County17.8+0.2 pts
64Wayne County17.5-0.2 pts
65Sullivan County16+0.5 pts
66Centre County15.4-0.1 pts
67Forest County9.5-0.2 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, 2015) [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, 2015. 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=2015. 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, 2015. 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=2015.

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, 2015 [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=2015 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_pennsylvania_by_2015,
  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, 2015}},
  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=2015. 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, 2015
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=2015
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2015.
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 23.8% in 2015, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Forest County, with 9.5% in 2015.

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