Story County, IA population age distribution
A complete breakdown of Story County's age demographics from 0 to 85 years, distributed across 18 age groups is listed in the table below.
Age Group | Population | % of Total Population |
---|---|---|
Under 5 years | 4,368 | 4.45% |
5 to 9 years | 4,974 | 5.07% |
10 to 14 years | 4,306 | 4.39% |
15 to 19 years | 10,908 | 11.12% |
20 to 24 years | 21,309 | 21.72% |
25 to 29 years | 7,521 | 7.67% |
30 to 34 years | 5,302 | 5.4% |
35 to 39 years | 5,775 | 5.89% |
40 to 44 years | 4,217 | 4.3% |
45 to 49 years | 4,055 | 4.13% |
50 to 54 years | 4,076 | 4.15% |
55 to 59 years | 4,665 | 4.76% |
60 to 64 years | 4,600 | 4.69% |
65 to 69 years | 4,156 | 4.24% |
70 to 74 years | 2,892 | 2.95% |
75 to 79 years | 1,768 | 1.8% |
80 to 84 years | 1,525 | 1.55% |
85 years and over | 1,689 | 1.72% |
TABLE OF CONTENTS
Story County, IA population by age group
Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

The largest age group in Story County, IA was for the group of age 20-24 years with a population of 21,309 (21.72%), according to the 2021 American Community Survey.
At the same time, the smallest age group in Story County, IA was the 80-84 years with a population of 1,525 (1.55%).
Story County, IA population by age cohort
To better understand the age distribution of Story County, IA's population, we divided it into the following 3 cohorts:
- Children : Under the age of 18 years
- Adults (working population): Between the age of 18 and 64 years
- Seniors: 65 years and above

Here's the population for each of the three cohorts.
Age Group | Population | % of Total Population |
---|---|---|
Under 18 years | 16,316 | 16.63% |
18 to 64 years | 69,760 | 71.11% |
85 years and over | 12,030 | 12.26% |
Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:
- Story County's population under 18 was 16.63%, compared to the 22.51% nationwide.
- Story County's working population (between 18 and 64) was 71.11%, compared to 61.45% nationwide.
- Story County's elderly or the senior population (over 65 age) was 12.26% as compared to 16.04% nationwide.
Story County, IA population pyramid
Population pyramid for Story County, IA is charted below using the estimates from U.S. Census Bureau's American Community Survey 5-Year estimates. A wide base suggests population increase, narrow base indicates declining birth rates.
Key stats from our analysis of the Story County's population pyramid:
- Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Story County, IA, is 18.8.
- Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Story County, IA, is 16.6.
- Total dependency ratio for Story County, IA is 35.5.
- Potential support ratio, which is the number of youth (working age population) per elderly, for Story County, IA is 6.0.

Here's the Story County, IA's male and female population across different age groups:
Age Group | Population(Male) | Population(Female) | Total Population |
---|---|---|---|
Under 5 years | 2,229 | 2,139 | 4,368 |
5 to 9 years | 2,606 | 2,368 | 4,974 |
10 to 14 years | 2,141 | 2,165 | 4,306 |
15 to 19 years | 5,629 | 5,279 | 10,908 |
20 to 24 years | 12,215 | 9,094 | 21,309 |
25 to 29 years | 4,203 | 3,318 | 7,521 |
30 to 34 years | 2,876 | 2,426 | 5,302 |
35 to 39 years | 3,215 | 2,560 | 5,775 |
40 to 44 years | 2,031 | 2,186 | 4,217 |
45 to 49 years | 2,069 | 1,986 | 4,055 |
50 to 54 years | 2,079 | 1,997 | 4,076 |
55 to 59 years | 2,147 | 2,518 | 4,665 |
60 to 64 years | 2,490 | 2,110 | 4,600 |
65 to 69 years | 2,046 | 2,110 | 4,156 |
70 to 74 years | 1,311 | 1,581 | 2,892 |
75 to 79 years | 841 | 927 | 1,768 |
80 to 84 years | 621 | 904 | 1,525 |
85 years and over | 620 | 1,069 | 1,689 |
Things to know
What is the population of Story County, IA under 18?
Story County's population under the age of 18 is 16,316, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 16.63% of the total resident population of Story County, IA.
What is the aging population in Story County, IA?
Story County's population aged 65 years and above was 12,030. As per the U.S. Census Bureau's American Community Survey, this population is 12.26% of the entire population.
References
- U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates