Data / Rankings / Population under 18 / Counties in Michigan

Counties in Michigan by population under 18, 2025

St. Joseph County had the highest population under 18 of 83 counties in 2025, at 23.5%. Ontonagon County had the lowest, at 11.9%. The median was 19% and the figure for Michigan was 20.4%. Source: the U.S. Census Bureau.

Keep it in a collection in your library.
Highest23.5St. Joseph County
Lowest11.9Ontonagon County
Median1983 counties
Michigan20.4History

Map of counties, 2025

Alcona County: 13.1 %Alger County: 14.8 %Allegan County: 22 %Alpena County: 18.3 %Antrim County: 16.3 %Arenac County: 17.6 %Baraga County: 18.1 %Barry County: 20.7 %Bay County: 18.6 %Benzie County: 16.2 %Berrien County: 20.2 %Branch County: 23.5 %Calhoun County: 21.8 %Cass County: 20 %Charlevoix County: 17 %Cheboygan County: 15.5 %Chippewa County: 17.7 %Clare County: 19.1 %Clinton County: 20.6 %Crawford County: 17.6 %Delta County: 18.1 %Dickinson County: 19 %Eaton County: 20.3 %Emmet County: 16.8 %Genesee County: 21.1 %Gladwin County: 18.8 %Gogebic County: 16.1 %Grand Traverse County: 18.5 %Gratiot County: 14.7 %Hillsdale County: 21.4 %Houghton County: 19.3 %Huron County: 18.3 %Ingham County: 19 %Ionia County: 20.3 %Iosco County: 17 %Iron County: 16.3 %Isabella County: 18.9 %Jackson County: 20.2 %Kalamazoo County: 20.8 %Kalkaska County: 18.9 %Kent County: 22.5 %Keweenaw County: 15.1 %Lake County: 14.8 %Lapeer County: 19.4 %Leelanau County: 15 %Lenawee County: 19.9 %Livingston County: 19.6 %Luce County: 15.4 %Mackinac County: 14.8 %Macomb County: 19.8 %Manistee County: 16.1 %Marquette County: 16.9 %Mason County: 18 %Mecosta County: 19 %Menominee County: 16.8 %Midland County: 20.6 %Missaukee County: 21.3 %Monroe County: 20 %Montcalm County: 19.9 %Montmorency County: 14.7 %Muskegon County: 21.3 %Newaygo County: 21.4 %Oakland County: 19.4 %Oceana County: 20.7 %Ogemaw County: 17.8 %Ontonagon County: 11.9 %Osceola County: 22.2 %Oscoda County: 19.2 %Otsego County: 19.7 %Ottawa County: 21.8 %Presque Isle County: 14.8 %Roscommon County: 14 %Saginaw County: 19.7 %St. Clair County: 19.3 %St. Joseph County: 23.5 %Sanilac County: 20.3 %Schoolcraft County: 17.1 %Shiawassee County: 20.2 %Tuscola County: 19.8 %Van Buren County: 22 %Washtenaw County: 17.2 %Wayne County: 22.6 %Wexford County: 21.9 %
  • Under 16
  • 16 to 18
  • 18 to 19
  • 19 to 20
  • 20 to 21
  • 21 and over
%, 2025. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2025

St. Joseph County: 23.5 %St. Joseph County23.5Branch County: 23.5 %Branch County23.5Wayne County: 22.6 %Wayne County22.6Kent County: 22.5 %Kent County22.5Osceola County: 22.2 %Osceola County22.2Allegan County: 22 %Allegan County22Van Buren County: 22 %Van Buren County22Wexford County: 21.9 %Wexford County21.9Calhoun County: 21.8 %Calhoun County21.8Ottawa County: 21.8 %Ottawa County21.8Hillsdale County: 21.4 %Hillsdale County21.4Newaygo County: 21.4 %Newaygo County21.4Muskegon County: 21.3 %Muskegon County21.3Missaukee County: 21.3 %Missaukee County21.3Genesee County: 21.1 %Genesee County21.1Kalamazoo County: 20.8 %Kalamazoo County20.8Barry County: 20.7 %Barry County20.7Oceana County: 20.7 %Oceana County20.7Midland County: 20.6 %Midland County20.6Clinton County: 20.6 %Clinton County20.6Sanilac County: 20.3 %Sanilac County20.3Eaton County: 20.3 %Eaton County20.3Ionia County: 20.3 %Ionia County20.3Berrien County: 20.2 %Berrien County20.2Jackson County: 20.2 %Jackson County20.2Shiawassee County: 20.2 %Shiawassee County20.2Cass County: 20 %Cass County20Monroe County: 20 %Monroe County20Montcalm County: 19.9 %Montcalm County19.9Lenawee County: 19.9 %Lenawee County19.9Tuscola County: 19.8 %Tuscola County19.8Macomb County: 19.8 %Macomb County19.8Otsego County: 19.7 %Otsego County19.7Saginaw County: 19.7 %Saginaw County19.7Livingston County: 19.6 %Livingston County19.6Lapeer County: 19.4 %Lapeer County19.4Oakland County: 19.4 %Oakland County19.4Houghton County: 19.3 %Houghton County19.3St. Clair County: 19.3 %St. Clair County19.3Oscoda County: 19.2 %Oscoda County19.2St. Joseph County: 23.5 %St. Joseph County23.5Branch County: 23.5 %Branch County23.5Wayne County: 22.6 %Wayne County22.6Kent County: 22.5 %Kent County22.5Osceola County: 22.2 %Osceola County22.2Allegan County: 22 %Allegan County22Van Buren County: 22 %Van Buren County22Wexford County: 21.9 %Wexford County21.9Calhoun County: 21.8 %Calhoun County21.8Ottawa County: 21.8 %Ottawa County21.8Hillsdale County: 21.4 %Hillsdale County21.4Newaygo County: 21.4 %Newaygo County21.4Muskegon County: 21.3 %Muskegon County21.3Missaukee County: 21.3 %Missaukee County21.3Genesee County: 21.1 %Genesee County21.1Kalamazoo County: 20.8 %Kalamazoo County20.8Barry County: 20.7 %Barry County20.7Oceana County: 20.7 %Oceana County20.7Midland County: 20.6 %Midland County20.6Clinton County: 20.6 %Clinton County20.6Sanilac County: 20.3 %Sanilac County20.3Eaton County: 20.3 %Eaton County20.3Ionia County: 20.3 %Ionia County20.3Berrien County: 20.2 %Berrien County20.2Jackson County: 20.2 %Jackson County20.2Shiawassee County: 20.2 %Shiawassee County20.2Cass County: 20 %Cass County20Monroe County: 20 %Monroe County20Montcalm County: 19.9 %Montcalm County19.9Lenawee County: 19.9 %Lenawee County19.9Tuscola County: 19.8 %Tuscola County19.8Macomb County: 19.8 %Macomb County19.8Otsego County: 19.7 %Otsego County19.7Saginaw County: 19.7 %Saginaw County19.7Livingston County: 19.6 %Livingston County19.6Lapeer County: 19.4 %Lapeer County19.4Oakland County: 19.4 %Oakland County19.4Houghton County: 19.3 %Houghton County19.3St. Clair County: 19.3 %St. Clair County19.3Oscoda County: 19.2 %Oscoda County19.2
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2025 (%)Change on 2024
1St. Joseph County23.5-0.3 pts
2Branch County23.5-0 pts
3Wayne County22.6-0.2 pts
4Kent County22.5-0.3 pts
5Osceola County22.2-0.3 pts
6Allegan County22-0.4 pts
7Van Buren County22-0.3 pts
8Wexford County21.9-0.3 pts
9Calhoun County21.8-0.4 pts
10Ottawa County21.8-0.4 pts
11Hillsdale County21.4-0.4 pts
12Newaygo County21.4-0.3 pts
13Muskegon County21.3-0.3 pts
14Missaukee County21.3-0.2 pts
15Genesee County21.1-0.3 pts
16Kalamazoo County20.8-0.2 pts
17Barry County20.7-0.6 pts
18Oceana County20.7-0.2 pts
19Midland County20.6-0.2 pts
20Clinton County20.6-0.4 pts
21Sanilac County20.3-0.1 pts
22Eaton County20.3-0.2 pts
23Ionia County20.3-0.4 pts
24Berrien County20.2-0.3 pts
25Jackson County20.2-0.1 pts
26Shiawassee County20.2-0.1 pts
27Cass County20-0 pts
28Monroe County20-0.3 pts
29Montcalm County19.9-0.3 pts
30Lenawee County19.9-0.3 pts
31Tuscola County19.8-0.3 pts
32Macomb County19.8-0.2 pts
33Otsego County19.7-0.4 pts
33Saginaw County19.7-0.4 pts
35Livingston County19.6-0.3 pts
36Lapeer County19.4-0.2 pts
37Oakland County19.4-0.2 pts
38Houghton County19.3-0.2 pts
39St. Clair County19.3-0.3 pts
40Oscoda County19.2+0.1 pts
41Clare County19.1-0.5 pts
42Dickinson County19-0.4 pts
43Ingham County19-0.3 pts
44Mecosta County19-0.2 pts
45Kalkaska County18.9-0.4 pts
46Isabella County18.9-0.2 pts
47Gladwin County18.8-0 pts
48Bay County18.6-0.3 pts
49Grand Traverse County18.5-0.2 pts
50Huron County18.3-0 pts
51Alpena County18.3-0.2 pts
52Delta County18.1-0.4 pts
53Baraga County18.1+0.4 pts
54Mason County18-0.3 pts
55Ogemaw County17.8+0.1 pts
56Chippewa County17.7-0.4 pts
57Crawford County17.6-0.4 pts
58Arenac County17.6-0.3 pts
59Washtenaw County17.2-0.2 pts
60Schoolcraft County17.1-0.2 pts
61Iosco County17-0.2 pts
62Charlevoix County17-0.2 pts
63Marquette County16.9-0.3 pts
64Menominee County16.8-0.4 pts
65Emmet County16.8-0.3 pts
66Antrim County16.3-0 pts
67Iron County16.3-0.5 pts
68Benzie County16.2-0.2 pts
69Gogebic County16.1-0.2 pts
70Manistee County16.1-0.1 pts
71Cheboygan County15.5-0.5 pts
72Luce County15.4+0.1 pts
73Keweenaw County15.1-0 pts
74Leelanau County15-0.3 pts
75Mackinac County14.8-0.3 pts
76Lake County14.8-0.3 pts
77Alger County14.8+0.1 pts
78Presque Isle County14.8-0.4 pts
79Gratiot County14.7-1.1 pts
80Montmorency County14.7-0.3 pts
81Roscommon County14+0.1 pts
82Alcona County13.10 pts
83Ontonagon County11.9+0.1 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 Michigan by population under 18, 2025) [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 Michigan by population under 18, 2025. 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/michigan-counties. 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 Michigan by population under 18, 2025. 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/michigan-counties.

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 Michigan by population under 18, 2025 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/michigan-counties (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_michigan_by_2025,
  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 Michigan by population under 18, 2025}},
  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/michigan-counties. 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 Michigan by population under 18, 2025
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/michigan-counties
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/michigan-counties.
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 Michigan by population under 18 using official data, and cite the source.
rank_places {"indicator":"population_0_17_share","level":"province","within":"Michigan","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_0_17_share&level=province&within=Michigan&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?

St. Joseph County, with 23.5% in 2025, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Ontonagon County, with 11.9% in 2025.

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 Michigan: more rankings