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 2020, at 23.2%. Forest County had the lowest, at 8%. The median was 19.8% and the figure for Pennsylvania was 20.5%. Source: the U.S. Census Bureau.

Keep it in a collection in your library.
Highest23.2Lancaster County
Lowest8Forest County
Median19.867 counties
Pennsylvania20.5History

Map of counties, 2020

Adams County: 19.9 %Allegheny County: 18.5 %Armstrong County: 18.8 %Beaver County: 19.1 %Bedford County: 19.5 %Berks County: 22.2 %Blair County: 20 %Bradford County: 21.8 %Bucks County: 20.2 %Butler County: 19.8 %Cambria County: 18.8 %Cameron County: 17.6 %Carbon County: 19.2 %Centre County: 15.1 %Chester County: 22.7 %Clarion County: 19.7 %Clearfield County: 18 %Clinton County: 21 %Columbia County: 18 %Crawford County: 20.6 %Cumberland County: 20.5 %Dauphin County: 21.8 %Delaware County: 22.2 %Elk County: 18.5 %Erie County: 21 %Fayette County: 19 %Forest County: 8 %Franklin County: 22.4 %Fulton County: 20.8 %Greene County: 18.7 %Huntingdon County: 18.4 %Indiana County: 18.7 %Jefferson County: 20.9 %Juniata County: 22.2 %Lackawanna County: 19.7 %Lancaster County: 23.2 %Lawrence County: 19.9 %Lebanon County: 22.5 %Lehigh County: 22.4 %Luzerne County: 19.7 %Lycoming County: 20.6 %McKean County: 20 %Mercer County: 19.4 %Mifflin County: 22.2 %Monroe County: 20.2 %Montgomery County: 21.3 %Montour County: 20.6 %Northampton County: 19.6 %Northumberland County: 20 %Perry County: 21.7 %Philadelphia County: 20.8 %Pike County: 18.5 %Potter County: 19.8 %Schuylkill County: 19.1 %Snyder County: 21.6 %Somerset County: 18.1 %Sullivan County: 15.2 %Susquehanna County: 19.5 %Tioga County: 20.1 %Union County: 18.7 %Venango County: 19.8 %Warren County: 19.5 %Washington County: 19.3 %Wayne County: 16.7 %Westmoreland County: 18.2 %Wyoming County: 19.2 %York County: 21.9 %
  • Under 18
  • 18 to 19
  • 19 to 20
  • 20 to 21
  • 21 to 22
  • 22 and over
%, 2020. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2020

Lancaster County: 23.2 %Lancaster County23.2Chester County: 22.7 %Chester County22.7Lebanon County: 22.5 %Lebanon County22.5Franklin County: 22.4 %Franklin County22.4Lehigh County: 22.4 %Lehigh County22.4Juniata County: 22.2 %Juniata County22.2Mifflin County: 22.2 %Mifflin County22.2Berks County: 22.2 %Berks County22.2Delaware County: 22.2 %Delaware County22.2York County: 21.9 %York County21.9Bradford County: 21.8 %Bradford County21.8Dauphin County: 21.8 %Dauphin County21.8Perry County: 21.7 %Perry County21.7Snyder County: 21.6 %Snyder County21.6Montgomery County: 21.3 %Montgomery County21.3Clinton County: 21 %Clinton County21Erie County: 21 %Erie County21Jefferson County: 20.9 %Jefferson County20.9Philadelphia County: 20.8 %Philadelphia County20.8Fulton County: 20.8 %Fulton County20.8Crawford County: 20.6 %Crawford County20.6Montour County: 20.6 %Montour County20.6Lycoming County: 20.6 %Lycoming County20.6Cumberland County: 20.5 %Cumberland County20.5Bucks County: 20.2 %Bucks County20.2Monroe County: 20.2 %Monroe County20.2Tioga County: 20.1 %Tioga County20.1McKean County: 20 %McKean County20Northumberland County: 20 %Northumberland County20Blair County: 20 %Blair County20Lawrence County: 19.9 %Lawrence County19.9Adams County: 19.9 %Adams County19.9Butler County: 19.8 %Butler County19.8Potter County: 19.8 %Potter County19.8Venango County: 19.8 %Venango County19.8Lackawanna County: 19.7 %Lackawanna County19.7Luzerne County: 19.7 %Luzerne County19.7Clarion County: 19.7 %Clarion County19.7Northampton County: 19.6 %Northampton County19.6Susquehanna County: 19.5 %Susquehanna County19.5Lancaster County: 23.2 %Lancaster County23.2Chester County: 22.7 %Chester County22.7Lebanon County: 22.5 %Lebanon County22.5Franklin County: 22.4 %Franklin County22.4Lehigh County: 22.4 %Lehigh County22.4Juniata County: 22.2 %Juniata County22.2Mifflin County: 22.2 %Mifflin County22.2Berks County: 22.2 %Berks County22.2Delaware County: 22.2 %Delaware County22.2York County: 21.9 %York County21.9Bradford County: 21.8 %Bradford County21.8Dauphin County: 21.8 %Dauphin County21.8Perry County: 21.7 %Perry County21.7Snyder County: 21.6 %Snyder County21.6Montgomery County: 21.3 %Montgomery County21.3Clinton County: 21 %Clinton County21Erie County: 21 %Erie County21Jefferson County: 20.9 %Jefferson County20.9Philadelphia County: 20.8 %Philadelphia County20.8Fulton County: 20.8 %Fulton County20.8Crawford County: 20.6 %Crawford County20.6Montour County: 20.6 %Montour County20.6Lycoming County: 20.6 %Lycoming County20.6Cumberland County: 20.5 %Cumberland County20.5Bucks County: 20.2 %Bucks County20.2Monroe County: 20.2 %Monroe County20.2Tioga County: 20.1 %Tioga County20.1McKean County: 20 %McKean County20Northumberland County: 20 %Northumberland County20Blair County: 20 %Blair County20Lawrence County: 19.9 %Lawrence County19.9Adams County: 19.9 %Adams County19.9Butler County: 19.8 %Butler County19.8Potter County: 19.8 %Potter County19.8Venango County: 19.8 %Venango County19.8Lackawanna County: 19.7 %Lackawanna County19.7Luzerne County: 19.7 %Luzerne County19.7Clarion County: 19.7 %Clarion County19.7Northampton County: 19.6 %Northampton County19.6Susquehanna County: 19.5 %Susquehanna County19.5
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2020 (%)Change on 2019
1Lancaster County23.2-0.1 pts
2Chester County22.7-0.1 pts
3Lebanon County22.5+0.1 pts
4Franklin County22.4-0.1 pts
5Lehigh County22.4+0.2 pts
6Juniata County22.2+0.1 pts
7Mifflin County22.2+0.4 pts
8Berks County22.2-0.1 pts
9Delaware County22.2+0.1 pts
10York County21.9-0.1 pts
11Bradford County21.8+0.2 pts
12Dauphin County21.8+0.1 pts
13Perry County21.7-0.1 pts
14Snyder County21.6+0.1 pts
15Montgomery County21.3-0.1 pts
16Clinton County21+0.1 pts
17Erie County21-0 pts
18Jefferson County20.9+0.1 pts
19Philadelphia County20.8+0.3 pts
20Fulton County20.80 pts
21Crawford County20.60 pts
22Montour County20.6-0.1 pts
23Lycoming County20.6+0.1 pts
24Cumberland County20.5+0.1 pts
25Bucks County20.2-0.2 pts
26Monroe County20.2-0.1 pts
27Tioga County20.1-0.2 pts
28McKean County20-0.1 pts
29Northumberland County20-0.1 pts
30Blair County20+0.1 pts
31Lawrence County19.9+0.2 pts
32Adams County19.9-0.2 pts
33Butler County19.8-0.2 pts
34Potter County19.8-0.2 pts
35Venango County19.8-0.3 pts
36Lackawanna County19.70 pts
37Luzerne County19.7+0.3 pts
38Clarion County19.7+0.3 pts
39Northampton County19.6-0.1 pts
40Susquehanna County19.5+0.2 pts
41Bedford County19.50 pts
42Warren County19.5+0.2 pts
43Mercer County19.4-0.2 pts
44Washington County19.3+0.1 pts
45Carbon County19.2-0.1 pts
46Wyoming County19.20 pts
47Schuylkill County19.1+0.2 pts
48Beaver County19.1-0.1 pts
49Fayette County19+0.2 pts
50Armstrong County18.80 pts
51Cambria County18.8-0.1 pts
52Greene County18.7-0 pts
53Union County18.70 pts
54Indiana County18.70 pts
55Pike County18.5-0.4 pts
56Elk County18.5-0.2 pts
57Allegheny County18.5-0 pts
58Huntingdon County18.4+0.2 pts
59Westmoreland County18.2-0.2 pts
60Somerset County18.1+0.1 pts
61Clearfield County18-0.1 pts
62Columbia County18-0.1 pts
63Cameron County17.6-0.2 pts
64Wayne County16.7-0.1 pts
65Sullivan County15.2-1.6 pts
66Centre County15.1-0.2 pts
67Forest County8-1.3 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, 2020) [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, 2020. 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=2020. 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, 2020. 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=2020.

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, 2020 [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=2020 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_pennsylvania_by_2020,
  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, 2020}},
  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=2020. 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, 2020
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=2020
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/pennsylvania-counties?period=2020.
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  -
Embed this chart

Paste this code into a web page or a blog post. The chart shows the latest figures as they are published, with the source and a link back to this page.

Sites that read oEmbed links, such as WordPress, can show the chart when you paste the link to this page.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Pennsylvania by population under 18 using official data, and cite the source.
rank_places {"indicator":"population_0_17_share","level":"province","within":"Pennsylvania","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_0_17_share&level=province&within=Pennsylvania&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest population under 18?

Lancaster County, with 23.2% in 2020, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Forest County, with 8% in 2020.

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