Data / Rankings / Population aged 18 to 64 / Counties in Iowa

Counties in Iowa by population aged 18 to 64

Story County had the highest population aged 18 to 64 of 99 counties in 2024, at 69.3%. Ringgold County had the lowest, at 50%. The median was 54% and the figure for Iowa was 57.9%. Source: the U.S. Census Bureau.

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Highest69.3Story County
Lowest50Ringgold County
Median5499 counties
Iowa57.9History

Map of counties, 2024

Adair County: 53.2 %Adams County: 53.1 %Allamakee County: 51.1 %Appanoose County: 53.6 %Audubon County: 51.5 %Benton County: 56.3 %Black Hawk County: 59.2 %Boone County: 56.5 %Bremer County: 55.8 %Buchanan County: 53.9 %Buena Vista County: 56.2 %Butler County: 51.6 %Calhoun County: 53.4 %Carroll County: 53.1 %Cass County: 52.4 %Cedar County: 56.1 %Cerro Gordo County: 54.2 %Cherokee County: 50.9 %Chickasaw County: 52.7 %Clarke County: 54.1 %Clay County: 54.1 %Clayton County: 51.2 %Clinton County: 55.4 %Crawford County: 54 %Dallas County: 60.1 %Davis County: 51.1 %Decatur County: 55.5 %Delaware County: 53.9 %Des Moines County: 55.6 %Dickinson County: 51.2 %Dubuque County: 57.1 %Emmet County: 53.7 %Fayette County: 54.4 %Floyd County: 53.2 %Franklin County: 53.3 %Fremont County: 53.1 %Greene County: 51.8 %Grundy County: 53 %Guthrie County: 52.4 %Hamilton County: 53.7 %Hancock County: 51.8 %Hardin County: 54.4 %Harrison County: 54.6 %Henry County: 57.3 %Howard County: 52.9 %Humboldt County: 53.1 %Ida County: 52.8 %Iowa County: 54.9 %Jackson County: 54 %Jasper County: 57.2 %Jefferson County: 51.7 %Johnson County: 66.1 %Jones County: 57.4 %Keokuk County: 53.5 %Kossuth County: 51.7 %Lee County: 54 %Linn County: 59.3 %Louisa County: 56.8 %Lucas County: 52.7 %Lyon County: 53.3 %Madison County: 55.8 %Mahaska County: 55.9 %Marion County: 55.9 %Marshall County: 55.3 %Mills County: 55.5 %Mitchell County: 51.7 %Monona County: 52.2 %Monroe County: 54.8 %Montgomery County: 53.4 %Muscatine County: 57.3 %O'Brien County: 53.8 %Osceola County: 55.7 %Page County: 55.6 %Palo Alto County: 52.4 %Plymouth County: 54.6 %Pocahontas County: 51.6 %Polk County: 61 %Pottawattamie County: 57.6 %Poweshiek County: 57.6 %Ringgold County: 50 %Sac County: 51.8 %Scott County: 58.4 %Shelby County: 52.7 %Sioux County: 55.7 %Story County: 69.3 %Tama County: 54.2 %Taylor County: 52.1 %Union County: 56 %Van Buren County: 51 %Wapello County: 57.2 %Warren County: 57.5 %Washington County: 53.6 %Wayne County: 51.1 %Webster County: 57.7 %Winnebago County: 55.2 %Winneshiek County: 55.7 %Woodbury County: 58.2 %Worth County: 53.4 %Wright County: 52.5 %
  • Under 52
  • 52 to 53
  • 53 to 54
  • 54 to 56
  • 56 to 57
  • 57 and over
%, 2024. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2024

Story County: 69.3 %Story County69.3Johnson County: 66.1 %Johnson County66.1Polk County: 61 %Polk County61Dallas County: 60.1 %Dallas County60.1Linn County: 59.3 %Linn County59.3Black Hawk County: 59.2 %Black Hawk County59.2Scott County: 58.4 %Scott County58.4Woodbury County: 58.2 %Woodbury County58.2Webster County: 57.7 %Webster County57.7Poweshiek County: 57.6 %Poweshiek County57.6Pottawattamie County: 57.6 %Pottawattamie County57.6Warren County: 57.5 %Warren County57.5Jones County: 57.4 %Jones County57.4Henry County: 57.3 %Henry County57.3Muscatine County: 57.3 %Muscatine County57.3Jasper County: 57.2 %Jasper County57.2Wapello County: 57.2 %Wapello County57.2Dubuque County: 57.1 %Dubuque County57.1Louisa County: 56.8 %Louisa County56.8Boone County: 56.5 %Boone County56.5Benton County: 56.3 %Benton County56.3Buena Vista County: 56.2 %Buena Vista County56.2Cedar County: 56.1 %Cedar County56.1Union County: 56 %Union County56Marion County: 55.9 %Marion County55.9Mahaska County: 55.9 %Mahaska County55.9Bremer County: 55.8 %Bremer County55.8Madison County: 55.8 %Madison County55.8Sioux County: 55.7 %Sioux County55.7Winneshiek County: 55.7 %Winneshiek County55.7Osceola County: 55.7 %Osceola County55.7Page County: 55.6 %Page County55.6Des Moines County: 55.6 %Des Moines County55.6Decatur County: 55.5 %Decatur County55.5Mills County: 55.5 %Mills County55.5Clinton County: 55.4 %Clinton County55.4Marshall County: 55.3 %Marshall County55.3Winnebago County: 55.2 %Winnebago County55.2Iowa County: 54.9 %Iowa County54.9Monroe County: 54.8 %Monroe County54.8Story County: 69.3 %Story County69.3Johnson County: 66.1 %Johnson County66.1Polk County: 61 %Polk County61Dallas County: 60.1 %Dallas County60.1Linn County: 59.3 %Linn County59.3Black Hawk County: 59.2 %Black Hawk County59.2Scott County: 58.4 %Scott County58.4Woodbury County: 58.2 %Woodbury County58.2Webster County: 57.7 %Webster County57.7Poweshiek County: 57.6 %Poweshiek County57.6Pottawattamie County: 57.6 %Pottawattamie County57.6Warren County: 57.5 %Warren County57.5Jones County: 57.4 %Jones County57.4Henry County: 57.3 %Henry County57.3Muscatine County: 57.3 %Muscatine County57.3Jasper County: 57.2 %Jasper County57.2Wapello County: 57.2 %Wapello County57.2Dubuque County: 57.1 %Dubuque County57.1Louisa County: 56.8 %Louisa County56.8Boone County: 56.5 %Boone County56.5Benton County: 56.3 %Benton County56.3Buena Vista County: 56.2 %Buena Vista County56.2Cedar County: 56.1 %Cedar County56.1Union County: 56 %Union County56Marion County: 55.9 %Marion County55.9Mahaska County: 55.9 %Mahaska County55.9Bremer County: 55.8 %Bremer County55.8Madison County: 55.8 %Madison County55.8Sioux County: 55.7 %Sioux County55.7Winneshiek County: 55.7 %Winneshiek County55.7Osceola County: 55.7 %Osceola County55.7Page County: 55.6 %Page County55.6Des Moines County: 55.6 %Des Moines County55.6Decatur County: 55.5 %Decatur County55.5Mills County: 55.5 %Mills County55.5Clinton County: 55.4 %Clinton County55.4Marshall County: 55.3 %Marshall County55.3Winnebago County: 55.2 %Winnebago County55.2Iowa County: 54.9 %Iowa County54.9Monroe County: 54.8 %Monroe County54.8
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2024 (%)Change on 2023
1Story County69.3-0.1 pts
2Johnson County66.1-0.4 pts
3Polk County61-0.1 pts
4Dallas County60.1-0 pts
5Linn County59.3-0.2 pts
6Black Hawk County59.2-0.1 pts
7Scott County58.4-0.2 pts
8Woodbury County58.2-0.1 pts
9Webster County57.7-0.1 pts
10Poweshiek County57.6-0.6 pts
11Pottawattamie County57.6-0.1 pts
12Warren County57.5+0.1 pts
13Jones County57.4-0.1 pts
14Henry County57.3-0.3 pts
15Muscatine County57.3-0.1 pts
16Jasper County57.2-0.2 pts
17Wapello County57.2+0.2 pts
18Dubuque County57.1-0.3 pts
19Louisa County56.8-0.3 pts
20Boone County56.5+0.1 pts
21Benton County56.3-0.4 pts
22Buena Vista County56.2-0.6 pts
23Cedar County56.1-0.1 pts
24Union County56-0 pts
25Marion County55.9-0.1 pts
26Mahaska County55.9-0.2 pts
27Bremer County55.8-0.2 pts
28Madison County55.8-0 pts
29Sioux County55.7-0.1 pts
30Winneshiek County55.7-0.8 pts
31Osceola County55.7+0.1 pts
32Page County55.6+0.2 pts
33Des Moines County55.6-0 pts
34Decatur County55.5-0.1 pts
35Mills County55.5-0.3 pts
36Clinton County55.4-0.3 pts
37Marshall County55.3+0.2 pts
38Winnebago County55.2-0.3 pts
39Iowa County54.9-0.9 pts
40Monroe County54.8-0.1 pts
41Plymouth County54.6-0.2 pts
42Harrison County54.6-0.5 pts
43Hardin County54.40 pts
44Fayette County54.4-0.2 pts
45Cerro Gordo County54.2-0.3 pts
46Tama County54.2+0.1 pts
47Clarke County54.1-0.1 pts
48Clay County54.1-0 pts
49Jackson County54-0.4 pts
49Lee County54-0.5 pts
51Crawford County54-0.3 pts
52Delaware County53.9-0.4 pts
53Buchanan County53.9-0.3 pts
54O'Brien County53.8-0.1 pts
55Hamilton County53.7-0.7 pts
56Emmet County53.7-0.3 pts
57Washington County53.6-0.4 pts
58Appanoose County53.6-0.3 pts
59Keokuk County53.5-0.4 pts
60Calhoun County53.4-0.2 pts
61Montgomery County53.4-0.4 pts
62Worth County53.4-0.4 pts
63Lyon County53.3+0.4 pts
64Franklin County53.3+0.4 pts
65Floyd County53.2-0.4 pts
66Adair County53.2-0.3 pts
67Adams County53.1-1 pts
68Humboldt County53.1-0.4 pts
69Carroll County53.1-0.3 pts
70Fremont County53.1+0.4 pts
71Grundy County530 pts
72Howard County52.9-0.5 pts
73Ida County52.8-0.1 pts
74Chickasaw County52.7-0.3 pts
75Lucas County52.7-0.6 pts
76Shelby County52.7-0.4 pts
77Wright County52.5+0.4 pts
78Cass County52.4-0.3 pts
79Palo Alto County52.4-0.4 pts
80Guthrie County52.4-0.4 pts
81Monona County52.2-0.2 pts
82Taylor County52.1+0.2 pts
83Greene County51.8-0.4 pts
84Sac County51.8-0.6 pts
85Hancock County51.8-0.7 pts
86Jefferson County51.7-0.4 pts
87Mitchell County51.7-0.3 pts
88Kossuth County51.7-0.6 pts
89Pocahontas County51.6-0.5 pts
90Butler County51.6-0.6 pts
91Audubon County51.5-0.3 pts
92Clayton County51.2-0.6 pts
93Dickinson County51.2-0.2 pts
94Allamakee County51.1-0.7 pts
95Wayne County51.1-0.1 pts
96Davis County51.1-0.1 pts
97Van Buren County51-0.2 pts
98Cherokee County50.9-0.3 pts
99Ringgold County50-0.7 pts

Other periods

About this ranking

Residents aged 18 to 64 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.

Not comparable with working-age shares for ages 15 to 64 used in EU and World Bank statistics.

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 18 to 64 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 18 to 64 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 Iowa by population aged 18 to 64, 2024) [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 18 to 64 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 Iowa by population aged 18 to 64, 2024. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-18-64/iowa-counties?period=2024. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 Iowa by population aged 18 to 64, 2024. 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-18-64/iowa-counties?period=2024.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 Iowa by population aged 18 to 64, 2024 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-18-64/iowa-counties?period=2024 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_iowa_by_2024,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 Iowa by population aged 18 to 64, 2024}},
  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-18-64/iowa-counties?period=2024. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 18 to 64 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 Iowa by population aged 18 to 64, 2024
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-18-64/iowa-counties?period=2024
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/iowa-counties?period=2024.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 Iowa by population aged 18 to 64 using official data, and cite the source.
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Questions

Which county has the highest population aged 18 to 64?

Story County, with 69.3% in 2024, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Ringgold County, with 50% in 2024.

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 18 to 64 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 aged 18 to 64: other rankings

Counties in Iowa: more rankings