Data / Rankings / Population under 18 / Counties in Ohio

Counties in Ohio by population under 18

Holmes County had the highest population under 18 of 88 counties in 2020, at 30.7%. Athens County had the lowest, at 15.6%. The median was 22.4% and the figure for Ohio was 22.1%. Source: the U.S. Census Bureau.

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Highest30.7Holmes County
Lowest15.6Athens County
Median22.488 counties
Ohio22.1History

Map of counties, 2020

Adams County: 24 %Allen County: 23.4 %Ashland County: 22.5 %Ashtabula County: 21.8 %Athens County: 15.6 %Auglaize County: 23.8 %Belmont County: 19.1 %Brown County: 22.9 %Butler County: 23.4 %Carroll County: 21 %Champaign County: 22.7 %Clark County: 22.4 %Clermont County: 22.8 %Clinton County: 22.3 %Columbiana County: 20.2 %Coshocton County: 24.4 %Crawford County: 21.3 %Cuyahoga County: 20.3 %Darke County: 23.7 %Defiance County: 23 %Delaware County: 26.4 %Erie County: 19.9 %Fairfield County: 24.2 %Fayette County: 23.4 %Franklin County: 23 %Fulton County: 23.5 %Gallia County: 23.5 %Geauga County: 22.4 %Greene County: 21.1 %Guernsey County: 21.7 %Hamilton County: 22.6 %Hancock County: 22 %Hardin County: 23.2 %Harrison County: 21.1 %Henry County: 23.3 %Highland County: 24 %Hocking County: 21.8 %Holmes County: 30.7 %Huron County: 23.5 %Jackson County: 23.8 %Jefferson County: 19.6 %Knox County: 23 %Lake County: 19.5 %Lawrence County: 22 %Licking County: 23 %Logan County: 22.4 %Lorain County: 21.7 %Lucas County: 22.7 %Madison County: 21 %Mahoning County: 19.8 %Marion County: 21.3 %Medina County: 21.9 %Meigs County: 21.3 %Mercer County: 25.5 %Miami County: 23.2 %Monroe County: 20.2 %Montgomery County: 21.9 %Morgan County: 20.6 %Morrow County: 22.8 %Muskingum County: 22.6 %Noble County: 19 %Ottawa County: 18.3 %Paulding County: 24 %Perry County: 23.8 %Pickaway County: 22.4 %Pike County: 24 %Portage County: 18.4 %Preble County: 22.5 %Putnam County: 25.4 %Richland County: 21.7 %Ross County: 21.2 %Sandusky County: 22.1 %Scioto County: 21.7 %Seneca County: 21.9 %Shelby County: 24.8 %Stark County: 21.4 %Summit County: 20.8 %Trumbull County: 20 %Tuscarawas County: 22.9 %Union County: 25.4 %Van Wert County: 23.7 %Vinton County: 22.2 %Warren County: 24.5 %Washington County: 19.9 %Wayne County: 24 %Williams County: 22.3 %Wood County: 20.6 %Wyandot County: 22.4 %
  • Under 21
  • 21 to 22
  • 22 to 23
  • 23 to 24
  • 24 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

Holmes County: 30.7 %Holmes County30.7Delaware County: 26.4 %Delaware County26.4Mercer County: 25.5 %Mercer County25.5Putnam County: 25.4 %Putnam County25.4Union County: 25.4 %Union County25.4Shelby County: 24.8 %Shelby County24.8Warren County: 24.5 %Warren County24.5Coshocton County: 24.4 %Coshocton County24.4Fairfield County: 24.2 %Fairfield County24.2Pike County: 24 %Pike County24Wayne County: 24 %Wayne County24Adams County: 24 %Adams County24Highland County: 24 %Highland County24Paulding County: 24 %Paulding County24Jackson County: 23.8 %Jackson County23.8Auglaize County: 23.8 %Auglaize County23.8Perry County: 23.8 %Perry County23.8Van Wert County: 23.7 %Van Wert County23.7Darke County: 23.7 %Darke County23.7Fulton County: 23.5 %Fulton County23.5Huron County: 23.5 %Huron County23.5Gallia County: 23.5 %Gallia County23.5Fayette County: 23.4 %Fayette County23.4Butler County: 23.4 %Butler County23.4Allen County: 23.4 %Allen County23.4Henry County: 23.3 %Henry County23.3Hardin County: 23.2 %Hardin County23.2Miami County: 23.2 %Miami County23.2Defiance County: 23 %Defiance County23Franklin County: 23 %Franklin County23Knox County: 23 %Knox County23Licking County: 23 %Licking County23Tuscarawas County: 22.9 %Tuscarawas County22.9Brown County: 22.9 %Brown County22.9Morrow County: 22.8 %Morrow County22.8Clermont County: 22.8 %Clermont County22.8Champaign County: 22.7 %Champaign County22.7Lucas County: 22.7 %Lucas County22.7Muskingum County: 22.6 %Muskingum County22.6Hamilton County: 22.6 %Hamilton County22.6Holmes County: 30.7 %Holmes County30.7Delaware County: 26.4 %Delaware County26.4Mercer County: 25.5 %Mercer County25.5Putnam County: 25.4 %Putnam County25.4Union County: 25.4 %Union County25.4Shelby County: 24.8 %Shelby County24.8Warren County: 24.5 %Warren County24.5Coshocton County: 24.4 %Coshocton County24.4Fairfield County: 24.2 %Fairfield County24.2Pike County: 24 %Pike County24Wayne County: 24 %Wayne County24Adams County: 24 %Adams County24Highland County: 24 %Highland County24Paulding County: 24 %Paulding County24Jackson County: 23.8 %Jackson County23.8Auglaize County: 23.8 %Auglaize County23.8Perry County: 23.8 %Perry County23.8Van Wert County: 23.7 %Van Wert County23.7Darke County: 23.7 %Darke County23.7Fulton County: 23.5 %Fulton County23.5Huron County: 23.5 %Huron County23.5Gallia County: 23.5 %Gallia County23.5Fayette County: 23.4 %Fayette County23.4Butler County: 23.4 %Butler County23.4Allen County: 23.4 %Allen County23.4Henry County: 23.3 %Henry County23.3Hardin County: 23.2 %Hardin County23.2Miami County: 23.2 %Miami County23.2Defiance County: 23 %Defiance County23Franklin County: 23 %Franklin County23Knox County: 23 %Knox County23Licking County: 23 %Licking County23Tuscarawas County: 22.9 %Tuscarawas County22.9Brown County: 22.9 %Brown County22.9Morrow County: 22.8 %Morrow County22.8Clermont County: 22.8 %Clermont County22.8Champaign County: 22.7 %Champaign County22.7Lucas County: 22.7 %Lucas County22.7Muskingum County: 22.6 %Muskingum County22.6Hamilton County: 22.6 %Hamilton County22.6
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2020 (%)Change on 2019
1Holmes County30.7-0.4 pts
2Delaware County26.4-0.5 pts
3Mercer County25.5+0.1 pts
4Putnam County25.4-0 pts
5Union County25.4-0.2 pts
6Shelby County24.8-0.1 pts
7Warren County24.5-0.4 pts
8Coshocton County24.4+0.1 pts
9Fairfield County24.2-0 pts
10Pike County24+0.3 pts
11Wayne County24-0.1 pts
12Adams County24+0.3 pts
13Highland County24+0.1 pts
14Paulding County240 pts
15Jackson County23.8+0.1 pts
16Auglaize County23.8+0.1 pts
17Perry County23.8-0.1 pts
18Van Wert County23.7-0 pts
19Darke County23.7+0.2 pts
20Fulton County23.5-0 pts
21Huron County23.5-0.2 pts
22Gallia County23.5+0.4 pts
23Fayette County23.40 pts
24Butler County23.4-0.1 pts
25Allen County23.4+0.2 pts
26Henry County23.3-0.1 pts
27Hardin County23.2+0.2 pts
28Miami County23.2-0.2 pts
29Defiance County23-0.2 pts
29Franklin County23+0.1 pts
31Knox County23+0.2 pts
32Licking County23-0.1 pts
33Tuscarawas County22.9+0.2 pts
34Brown County22.9-0.1 pts
35Morrow County22.8-0.3 pts
36Clermont County22.8-0.3 pts
37Champaign County22.7-0.1 pts
38Lucas County22.7+0.2 pts
39Muskingum County22.6+0.1 pts
40Hamilton County22.6+0.2 pts
41Preble County22.5-0.1 pts
42Ashland County22.5-0 pts
43Logan County22.4-0.2 pts
44Geauga County22.4-0.2 pts
45Clark County22.4+0.1 pts
46Wyandot County22.4-0.3 pts
47Pickaway County22.40 pts
48Williams County22.3-0.2 pts
49Clinton County22.3-0.1 pts
50Vinton County22.2+0.2 pts
51Sandusky County22.1-0.1 pts
52Lawrence County22+0.1 pts
53Hancock County22-0.1 pts
54Medina County21.9-0.3 pts
55Seneca County21.9-0 pts
56Montgomery County21.9+0.1 pts
57Ashtabula County21.8+0.1 pts
58Hocking County21.8-0.1 pts
59Guernsey County21.7-0.1 pts
60Scioto County21.7+0.3 pts
61Richland County21.7+0.1 pts
62Lorain County21.7-0.1 pts
63Stark County21.40 pts
64Crawford County21.3+0.2 pts
65Marion County21.3+0.4 pts
66Meigs County21.3-0.1 pts
67Ross County21.2-0 pts
68Greene County21.1+0.1 pts
69Harrison County21.1-0.1 pts
70Madison County21+0.1 pts
71Carroll County21-0 pts
72Summit County20.80 pts
73Morgan County20.6-0.2 pts
74Wood County20.6-0.1 pts
75Cuyahoga County20.3-0.1 pts
76Columbiana County20.20 pts
77Monroe County20.2+0.1 pts
78Trumbull County200 pts
79Erie County19.9-0.2 pts
80Washington County19.9-0.1 pts
81Mahoning County19.8+0.1 pts
82Jefferson County19.6+0.2 pts
83Lake County19.5-0.2 pts
84Belmont County19.1+0.1 pts
85Noble County19+0.2 pts
86Portage County18.4-0.2 pts
87Ottawa County18.3-0.2 pts
88Athens County15.6-0.2 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 Ohio 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 Ohio 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/ohio-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 Ohio 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/ohio-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 Ohio 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/ohio-counties?period=2020 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_ohio_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 Ohio 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/ohio-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 Ohio 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/ohio-counties?period=2020
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/ohio-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  -
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Rank Counties in Ohio by population under 18 using official data, and cite the source.
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Questions

Which county has the highest population under 18?

Holmes County, with 30.7% in 2020, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Athens County, with 15.6% 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 Ohio: more rankings