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 2023, at 69.4%. Ringgold County had the lowest, at 50.7%. The median was 54.3% and the figure for Iowa was 58.1%. Source: the U.S. Census Bureau.

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Highest69.4Story County
Lowest50.7Ringgold County
Median54.399 counties
Iowa58.1History

Map of counties, 2023

Adair County: 53.4 %Adams County: 54.2 %Allamakee County: 51.8 %Appanoose County: 53.9 %Audubon County: 51.7 %Benton County: 56.7 %Black Hawk County: 59.3 %Boone County: 56.4 %Bremer County: 56 %Buchanan County: 54.2 %Buena Vista County: 56.8 %Butler County: 52.2 %Calhoun County: 53.7 %Carroll County: 53.4 %Cass County: 52.7 %Cedar County: 56.2 %Cerro Gordo County: 54.5 %Cherokee County: 51.1 %Chickasaw County: 53.1 %Clarke County: 54.3 %Clay County: 54.1 %Clayton County: 51.8 %Clinton County: 55.7 %Crawford County: 54.3 %Dallas County: 60.1 %Davis County: 51.2 %Decatur County: 55.6 %Delaware County: 54.3 %Des Moines County: 55.7 %Dickinson County: 51.5 %Dubuque County: 57.4 %Emmet County: 54 %Fayette County: 54.6 %Floyd County: 53.6 %Franklin County: 52.9 %Fremont County: 52.7 %Greene County: 52.2 %Grundy County: 53 %Guthrie County: 52.8 %Hamilton County: 54.4 %Hancock County: 52.5 %Hardin County: 54.4 %Harrison County: 55 %Henry County: 57.7 %Howard County: 53.4 %Humboldt County: 53.5 %Ida County: 52.9 %Iowa County: 55.8 %Jackson County: 54.5 %Jasper County: 57.4 %Jefferson County: 52.1 %Johnson County: 66.4 %Jones County: 57.5 %Keokuk County: 53.9 %Kossuth County: 52.2 %Lee County: 54.5 %Linn County: 59.5 %Louisa County: 57.1 %Lucas County: 53.3 %Lyon County: 52.9 %Madison County: 55.8 %Mahaska County: 56.1 %Marion County: 56 %Marshall County: 55.1 %Mills County: 55.8 %Mitchell County: 52 %Monona County: 52.3 %Monroe County: 54.8 %Montgomery County: 53.8 %Muscatine County: 57.5 %O'Brien County: 54 %Osceola County: 55.6 %Page County: 55.4 %Palo Alto County: 52.8 %Plymouth County: 54.8 %Pocahontas County: 52.1 %Polk County: 61 %Pottawattamie County: 57.7 %Poweshiek County: 58.3 %Ringgold County: 50.7 %Sac County: 52.4 %Scott County: 58.6 %Shelby County: 53.1 %Sioux County: 55.8 %Story County: 69.4 %Tama County: 54 %Taylor County: 51.9 %Union County: 56 %Van Buren County: 51.2 %Wapello County: 57 %Warren County: 57.4 %Washington County: 54 %Wayne County: 51.3 %Webster County: 57.8 %Winnebago County: 55.5 %Winneshiek County: 56.6 %Woodbury County: 58.3 %Worth County: 53.8 %Wright County: 52.2 %
  • Under 52
  • 52 to 53
  • 53 to 54
  • 54 to 56
  • 56 to 57
  • 57 and over
%, 2023. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2023

Story County: 69.4 %Story County69.4Johnson County: 66.4 %Johnson County66.4Polk County: 61 %Polk County61Dallas County: 60.1 %Dallas County60.1Linn County: 59.5 %Linn County59.5Black Hawk County: 59.3 %Black Hawk County59.3Scott County: 58.6 %Scott County58.6Woodbury County: 58.3 %Woodbury County58.3Poweshiek County: 58.3 %Poweshiek County58.3Webster County: 57.8 %Webster County57.8Pottawattamie County: 57.7 %Pottawattamie County57.7Henry County: 57.7 %Henry County57.7Jones County: 57.5 %Jones County57.5Muscatine County: 57.5 %Muscatine County57.5Jasper County: 57.4 %Jasper County57.4Dubuque County: 57.4 %Dubuque County57.4Warren County: 57.4 %Warren County57.4Louisa County: 57.1 %Louisa County57.1Wapello County: 57 %Wapello County57Buena Vista County: 56.8 %Buena Vista County56.8Benton County: 56.7 %Benton County56.7Winneshiek County: 56.6 %Winneshiek County56.6Boone County: 56.4 %Boone County56.4Cedar County: 56.2 %Cedar County56.2Mahaska County: 56.1 %Mahaska County56.1Marion County: 56 %Marion County56Union County: 56 %Union County56Bremer County: 56 %Bremer County56Madison County: 55.8 %Madison County55.8Sioux County: 55.8 %Sioux County55.8Iowa County: 55.8 %Iowa County55.8Mills County: 55.8 %Mills County55.8Clinton County: 55.7 %Clinton County55.7Des Moines County: 55.7 %Des Moines County55.7Decatur County: 55.6 %Decatur County55.6Osceola County: 55.6 %Osceola County55.6Winnebago County: 55.5 %Winnebago County55.5Page County: 55.4 %Page County55.4Marshall County: 55.1 %Marshall County55.1Harrison County: 55 %Harrison County55Story County: 69.4 %Story County69.4Johnson County: 66.4 %Johnson County66.4Polk County: 61 %Polk County61Dallas County: 60.1 %Dallas County60.1Linn County: 59.5 %Linn County59.5Black Hawk County: 59.3 %Black Hawk County59.3Scott County: 58.6 %Scott County58.6Woodbury County: 58.3 %Woodbury County58.3Poweshiek County: 58.3 %Poweshiek County58.3Webster County: 57.8 %Webster County57.8Pottawattamie County: 57.7 %Pottawattamie County57.7Henry County: 57.7 %Henry County57.7Jones County: 57.5 %Jones County57.5Muscatine County: 57.5 %Muscatine County57.5Jasper County: 57.4 %Jasper County57.4Dubuque County: 57.4 %Dubuque County57.4Warren County: 57.4 %Warren County57.4Louisa County: 57.1 %Louisa County57.1Wapello County: 57 %Wapello County57Buena Vista County: 56.8 %Buena Vista County56.8Benton County: 56.7 %Benton County56.7Winneshiek County: 56.6 %Winneshiek County56.6Boone County: 56.4 %Boone County56.4Cedar County: 56.2 %Cedar County56.2Mahaska County: 56.1 %Mahaska County56.1Marion County: 56 %Marion County56Union County: 56 %Union County56Bremer County: 56 %Bremer County56Madison County: 55.8 %Madison County55.8Sioux County: 55.8 %Sioux County55.8Iowa County: 55.8 %Iowa County55.8Mills County: 55.8 %Mills County55.8Clinton County: 55.7 %Clinton County55.7Des Moines County: 55.7 %Des Moines County55.7Decatur County: 55.6 %Decatur County55.6Osceola County: 55.6 %Osceola County55.6Winnebago County: 55.5 %Winnebago County55.5Page County: 55.4 %Page County55.4Marshall County: 55.1 %Marshall County55.1Harrison County: 55 %Harrison County55
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2023 (%)Change on 2022
1Story County69.4-0.2 pts
2Johnson County66.4-0.3 pts
3Polk County61-0.1 pts
4Dallas County60.1+0.1 pts
5Linn County59.5-0.3 pts
6Black Hawk County59.3-0.2 pts
7Scott County58.6-0.3 pts
8Woodbury County58.3-0.1 pts
9Poweshiek County58.3-0.2 pts
10Webster County57.8-0.6 pts
11Pottawattamie County57.7-0.3 pts
12Henry County57.7-1.2 pts
13Jones County57.5-0.1 pts
14Muscatine County57.5-0 pts
15Jasper County57.4-0.3 pts
16Dubuque County57.4-0.4 pts
17Warren County57.40 pts
18Louisa County57.1-0.1 pts
19Wapello County57-0.1 pts
20Buena Vista County56.8-0.3 pts
21Benton County56.7-0.5 pts
22Winneshiek County56.6-1 pts
23Boone County56.4-0.4 pts
24Cedar County56.2-0.1 pts
25Mahaska County56.1-0.3 pts
26Marion County56-0.4 pts
27Union County56-0 pts
28Bremer County56-0.2 pts
29Madison County55.80 pts
29Sioux County55.8-0.3 pts
31Iowa County55.8-0.5 pts
32Mills County55.8-0.1 pts
33Clinton County55.7-0.2 pts
34Des Moines County55.7-0.2 pts
35Decatur County55.6-0.6 pts
36Osceola County55.6+0.2 pts
37Winnebago County55.5-0.5 pts
38Page County55.4-0.5 pts
39Marshall County55.1+0.2 pts
40Harrison County55-0.6 pts
41Monroe County54.8-0.3 pts
42Plymouth County54.8-0.3 pts
43Fayette County54.6-0.3 pts
44Lee County54.5-0.5 pts
45Cerro Gordo County54.5-0.6 pts
46Jackson County54.5-0.8 pts
47Hamilton County54.4-0.7 pts
48Hardin County54.4-0.3 pts
49Crawford County54.3-0.5 pts
50Delaware County54.3-0.7 pts
51Clarke County54.3-0 pts
52Buchanan County54.2-0.1 pts
53Adams County54.2-0 pts
54Clay County54.1-0 pts
55Tama County54-0.5 pts
56Emmet County54-0.4 pts
57Washington County54-0.2 pts
58O'Brien County54+0.3 pts
59Keokuk County53.9-0.2 pts
60Appanoose County53.9-0.4 pts
61Worth County53.8-0.9 pts
62Montgomery County53.8-0.4 pts
63Calhoun County53.7-1 pts
64Floyd County53.60 pts
65Humboldt County53.5-0.5 pts
66Howard County53.4-0 pts
67Adair County53.4-0.5 pts
68Carroll County53.4-0.3 pts
69Lucas County53.3-0.4 pts
70Shelby County53.1-0.4 pts
71Chickasaw County53.1-0.6 pts
72Grundy County53-0.5 pts
73Lyon County52.9+0.3 pts
74Franklin County52.9-0.6 pts
75Ida County52.9-0.3 pts
76Guthrie County52.8-0.7 pts
77Palo Alto County52.8-0.2 pts
78Cass County52.7-0.4 pts
79Fremont County52.7-0.3 pts
80Hancock County52.5-0.5 pts
81Sac County52.4-0.4 pts
82Monona County52.30 pts
83Greene County52.2-0.7 pts
84Kossuth County52.2-0.4 pts
85Butler County52.20 pts
86Wright County52.2-0.3 pts
87Pocahontas County52.1-0.4 pts
88Jefferson County52.1-0.2 pts
89Mitchell County52-0.3 pts
90Taylor County51.9-0.5 pts
91Clayton County51.8-0.8 pts
92Allamakee County51.8-0.5 pts
93Audubon County51.7-0.5 pts
94Dickinson County51.5-0.7 pts
95Wayne County51.3-0.4 pts
96Davis County51.2-0.1 pts
97Van Buren County51.2-0.3 pts
98Cherokee County51.1-0.8 pts
99Ringgold County50.7-0.8 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, 2023) [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, 2023. 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=2023. 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, 2023. 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=2023.

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, 2023 [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=2023 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_iowa_by_2023,
  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, 2023}},
  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=2023. 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, 2023
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=2023
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/iowa-counties?period=2023.
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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Questions

Which county has the highest population aged 18 to 64?

Story County, with 69.4% in 2023, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Ringgold County, with 50.7% in 2023.

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