Data / Rankings / Population under 18 / Counties in Michigan

Counties in Michigan by population under 18

St. Joseph County had the highest population under 18 of 83 counties in 2018, at 24.6%. Ontonagon County had the lowest, at 12.3%. The median was 20.1% and the figure for Michigan was 21.7%. Source: the U.S. Census Bureau.

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Highest24.6St. Joseph County
Lowest12.3Ontonagon County
Median20.183 counties
Michigan21.7History

Map of counties, 2018

Alcona County: 13 %Alger County: 15.4 %Allegan County: 24.4 %Alpena County: 18.8 %Antrim County: 17.9 %Arenac County: 17.7 %Baraga County: 18.1 %Barry County: 22.8 %Bay County: 20.3 %Benzie County: 18.1 %Berrien County: 21.8 %Branch County: 24.1 %Calhoun County: 23 %Cass County: 21.5 %Charlevoix County: 19 %Cheboygan County: 17.7 %Chippewa County: 18.7 %Clare County: 20.1 %Clinton County: 23 %Crawford County: 18.5 %Delta County: 19.8 %Dickinson County: 20 %Eaton County: 21.4 %Emmet County: 19 %Genesee County: 22.5 %Gladwin County: 18.9 %Gogebic County: 15.7 %Grand Traverse County: 20.1 %Gratiot County: 21.7 %Hillsdale County: 22.4 %Houghton County: 19.9 %Huron County: 19.2 %Ingham County: 20.1 %Ionia County: 21.9 %Iosco County: 16.9 %Iron County: 16.9 %Isabella County: 18.7 %Jackson County: 21.4 %Kalamazoo County: 22.1 %Kalkaska County: 20.5 %Kent County: 24.1 %Keweenaw County: 14.7 %Lake County: 15.9 %Lapeer County: 21.2 %Leelanau County: 16.7 %Lenawee County: 21.2 %Livingston County: 21.9 %Luce County: 19.4 %Mackinac County: 16.3 %Macomb County: 20.8 %Manistee County: 17.2 %Marquette County: 18.4 %Mason County: 20.1 %Mecosta County: 19.9 %Menominee County: 18.8 %Midland County: 21.8 %Missaukee County: 23.1 %Monroe County: 21.5 %Montcalm County: 21.8 %Montmorency County: 15.1 %Muskegon County: 22.8 %Newaygo County: 22.7 %Oakland County: 21 %Oceana County: 23.1 %Ogemaw County: 18.6 %Ontonagon County: 12.3 %Osceola County: 23.3 %Oscoda County: 17.9 %Otsego County: 20.8 %Ottawa County: 24.1 %Presque Isle County: 16 %Roscommon County: 14.4 %Saginaw County: 21.8 %St. Clair County: 20.8 %St. Joseph County: 24.6 %Sanilac County: 21.6 %Schoolcraft County: 16.9 %Shiawassee County: 21.2 %Tuscola County: 21.4 %Van Buren County: 23.3 %Washtenaw County: 18.6 %Wayne County: 23.5 %Wexford County: 23.2 %
  • Under 17
  • 17 to 19
  • 19 to 20
  • 20 to 22
  • 22 to 23
  • 23 and over
%, 2018. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2018

St. Joseph County: 24.6 %St. Joseph County24.6Allegan County: 24.4 %Allegan County24.4Kent County: 24.1 %Kent County24.1Ottawa County: 24.1 %Ottawa County24.1Branch County: 24.1 %Branch County24.1Wayne County: 23.5 %Wayne County23.5Van Buren County: 23.3 %Van Buren County23.3Osceola County: 23.3 %Osceola County23.3Wexford County: 23.2 %Wexford County23.2Oceana County: 23.1 %Oceana County23.1Missaukee County: 23.1 %Missaukee County23.1Calhoun County: 23 %Calhoun County23Clinton County: 23 %Clinton County23Muskegon County: 22.8 %Muskegon County22.8Barry County: 22.8 %Barry County22.8Newaygo County: 22.7 %Newaygo County22.7Genesee County: 22.5 %Genesee County22.5Hillsdale County: 22.4 %Hillsdale County22.4Kalamazoo County: 22.1 %Kalamazoo County22.1Ionia County: 21.9 %Ionia County21.9Livingston County: 21.9 %Livingston County21.9Saginaw County: 21.8 %Saginaw County21.8Montcalm County: 21.8 %Montcalm County21.8Midland County: 21.8 %Midland County21.8Berrien County: 21.8 %Berrien County21.8Gratiot County: 21.7 %Gratiot County21.7Sanilac County: 21.6 %Sanilac County21.6Cass County: 21.5 %Cass County21.5Monroe County: 21.5 %Monroe County21.5Tuscola County: 21.4 %Tuscola County21.4Jackson County: 21.4 %Jackson County21.4Eaton County: 21.4 %Eaton County21.4Shiawassee County: 21.2 %Shiawassee County21.2Lenawee County: 21.2 %Lenawee County21.2Lapeer County: 21.2 %Lapeer County21.2Oakland County: 21 %Oakland County21Macomb County: 20.8 %Macomb County20.8St. Clair County: 20.8 %St. Clair County20.8Otsego County: 20.8 %Otsego County20.8Kalkaska County: 20.5 %Kalkaska County20.5St. Joseph County: 24.6 %St. Joseph County24.6Allegan County: 24.4 %Allegan County24.4Kent County: 24.1 %Kent County24.1Ottawa County: 24.1 %Ottawa County24.1Branch County: 24.1 %Branch County24.1Wayne County: 23.5 %Wayne County23.5Van Buren County: 23.3 %Van Buren County23.3Osceola County: 23.3 %Osceola County23.3Wexford County: 23.2 %Wexford County23.2Oceana County: 23.1 %Oceana County23.1Missaukee County: 23.1 %Missaukee County23.1Calhoun County: 23 %Calhoun County23Clinton County: 23 %Clinton County23Muskegon County: 22.8 %Muskegon County22.8Barry County: 22.8 %Barry County22.8Newaygo County: 22.7 %Newaygo County22.7Genesee County: 22.5 %Genesee County22.5Hillsdale County: 22.4 %Hillsdale County22.4Kalamazoo County: 22.1 %Kalamazoo County22.1Ionia County: 21.9 %Ionia County21.9Livingston County: 21.9 %Livingston County21.9Saginaw County: 21.8 %Saginaw County21.8Montcalm County: 21.8 %Montcalm County21.8Midland County: 21.8 %Midland County21.8Berrien County: 21.8 %Berrien County21.8Gratiot County: 21.7 %Gratiot County21.7Sanilac County: 21.6 %Sanilac County21.6Cass County: 21.5 %Cass County21.5Monroe County: 21.5 %Monroe County21.5Tuscola County: 21.4 %Tuscola County21.4Jackson County: 21.4 %Jackson County21.4Eaton County: 21.4 %Eaton County21.4Shiawassee County: 21.2 %Shiawassee County21.2Lenawee County: 21.2 %Lenawee County21.2Lapeer County: 21.2 %Lapeer County21.2Oakland County: 21 %Oakland County21Macomb County: 20.8 %Macomb County20.8St. Clair County: 20.8 %St. Clair County20.8Otsego County: 20.8 %Otsego County20.8Kalkaska County: 20.5 %Kalkaska County20.5
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2018 (%)Change on 2017
1St. Joseph County24.6-0.1 pts
2Allegan County24.4-0.2 pts
3Kent County24.1-0.3 pts
4Ottawa County24.1-0.2 pts
5Branch County24.1-0.1 pts
6Wayne County23.5-0.1 pts
7Van Buren County23.3-0.3 pts
8Osceola County23.3-0.2 pts
9Wexford County23.2-0.2 pts
10Oceana County23.1-0.4 pts
11Missaukee County23.1-0.2 pts
12Calhoun County23-0.2 pts
13Clinton County23-0.1 pts
14Muskegon County22.8-0.2 pts
15Barry County22.8-0 pts
16Newaygo County22.7-0 pts
17Genesee County22.5-0.2 pts
18Hillsdale County22.4-0.2 pts
19Kalamazoo County22.1-0.1 pts
20Ionia County21.9-0.3 pts
21Livingston County21.9-0.4 pts
22Saginaw County21.8-0.1 pts
23Montcalm County21.8-0.4 pts
24Midland County21.8-0.2 pts
25Berrien County21.8-0.2 pts
26Gratiot County21.7+0.1 pts
27Sanilac County21.6-0.2 pts
28Cass County21.5-0.1 pts
29Monroe County21.5-0.1 pts
30Tuscola County21.40 pts
31Jackson County21.4-0.3 pts
32Eaton County21.4-0.2 pts
33Shiawassee County21.2-0.2 pts
34Lenawee County21.2-0.2 pts
35Lapeer County21.2-0.3 pts
36Oakland County21-0.3 pts
37Macomb County20.8-0.3 pts
38St. Clair County20.8-0.3 pts
39Otsego County20.8-0.2 pts
40Kalkaska County20.5-0.2 pts
41Bay County20.3-0.2 pts
42Clare County20.1+0.1 pts
42Mason County20.1+0.1 pts
44Grand Traverse County20.1-0.3 pts
45Ingham County20.1-0.1 pts
46Dickinson County20+0.1 pts
47Houghton County19.9-0.1 pts
48Mecosta County19.9-0.1 pts
49Delta County19.8-0.2 pts
50Luce County19.4+0.5 pts
51Huron County19.2-0.1 pts
52Emmet County19-0.4 pts
53Charlevoix County19-0.5 pts
54Gladwin County18.9-0 pts
55Alpena County18.8-0.1 pts
56Menominee County18.8-0 pts
57Isabella County18.7+0.3 pts
58Chippewa County18.7-0 pts
59Washtenaw County18.6-0.1 pts
60Ogemaw County18.6-0.1 pts
61Crawford County18.5-0.3 pts
62Marquette County18.4-0 pts
63Baraga County18.1-0.7 pts
64Benzie County18.1-0.2 pts
65Antrim County17.9-0.3 pts
66Oscoda County17.9-0.5 pts
67Arenac County17.70 pts
68Cheboygan County17.7-0.2 pts
69Manistee County17.2-0.3 pts
70Iron County16.9+0.3 pts
71Schoolcraft County16.9+0.1 pts
72Iosco County16.9-0.1 pts
73Leelanau County16.7-0.1 pts
74Mackinac County16.3-0.1 pts
75Presque Isle County16-0.1 pts
76Lake County15.9+0.2 pts
77Gogebic County15.70 pts
78Alger County15.4-0.1 pts
79Montmorency County15.1-0.1 pts
80Keweenaw County14.7-0.6 pts
81Roscommon County14.4-0.2 pts
82Alcona County13-0 pts
83Ontonagon County12.3-0.1 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, 2018) [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, 2018. 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?period=2018. 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, 2018. 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?period=2018.

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, 2018 [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?period=2018 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_michigan_by_2018,
  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, 2018}},
  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?period=2018. 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, 2018
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?period=2018
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/michigan-counties?period=2018.
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 Michigan by population under 18 using official data, and cite the source.
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Questions

Which county has the highest population under 18?

St. Joseph County, with 24.6% in 2018, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Ontonagon County, with 12.3% in 2018.

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