O Brien County, IA population age distribution
A complete breakdown of O Brien 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 | 906 | 6.41% |
5 to 9 years | 1,014 | 7.17% |
10 to 14 years | 897 | 6.34% |
15 to 19 years | 908 | 6.42% |
20 to 24 years | 742 | 5.25% |
25 to 29 years | 880 | 6.22% |
30 to 34 years | 827 | 5.85% |
35 to 39 years | 764 | 5.4% |
40 to 44 years | 791 | 5.59% |
45 to 49 years | 715 | 5.06% |
50 to 54 years | 795 | 5.62% |
55 to 59 years | 980 | 6.93% |
60 to 64 years | 1,051 | 7.43% |
65 to 69 years | 851 | 6.02% |
70 to 74 years | 628 | 4.44% |
75 to 79 years | 355 | 2.51% |
80 to 84 years | 389 | 2.75% |
85 years and over | 646 | 4.57% |
TABLE OF CONTENTS
O Brien County, IA population by age group
Sources: U.S. Census Bureau, American Community Survey (ACS) 2021
![O Brien County, IA population by age group The graph shows O Brien County's population by age group, with age group on x-axis and the respective age group's percent of the total population on y-axis](https://i.neilsberg.com/ch/obrien-county-ia-population-by-age-group.jpeg)
The largest age group in O Brien County, IA was for the group of age 60-64 years with a population of 1,051 (7.43%), according to the 2021 American Community Survey.
At the same time, the smallest age group in O Brien County, IA was the 75-79 years with a population of 355 (2.51%).
O Brien County, IA population by age cohort
To better understand the age distribution of O Brien 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
![O Brien County, IA population by age cohort The pie chart shows O Brien County's population divided into segments, with each segment representing an age cohort. The area of each segment is in the same proportion of a circle as the population of the cohort is of the total population.](https://i.neilsberg.com/ch/obrien-county-ia-population-by-age-cohorts.jpeg)
Here's the population for each of the three cohorts.
Age Group | Population | % of Total Population |
---|---|---|
Under 18 years | 3,405 | 24.08% |
18 to 64 years | 7,865 | 55.63% |
85 years and over | 2,869 | 20.29% |
Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:
- O Brien County's population under 18 was 24.08%, compared to the 22.51% nationwide.
- O Brien County's working population (between 18 and 64) was 55.63%, compared to 61.45% nationwide.
- O Brien County's elderly or the senior population (over 65 age) was 20.29% as compared to 16.04% nationwide.
O Brien County, IA population pyramid
Population pyramid for O Brien 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 O Brien County's population pyramid:
- Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for O Brien County, IA, is 33.3.
- Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for O Brien County, IA, is 33.9.
- Total dependency ratio for O Brien County, IA is 67.3.
- Potential support ratio, which is the number of youth (working age population) per elderly, for O Brien County, IA is 2.9.
![O Brien County, IA population pyramid The graph shows O Brien County's population across different age group and gender, with population on x-axis and population y-axis. The male population is plotted on the left in blue color whereas the female population is plotted on the right in pink color.](https://i.neilsberg.com/ch/obrien-county-ia-population-by-age-and-gender-population-pyramid.jpeg)
Here's the O Brien County, IA's male and female population across different age groups:
Age Group | Population(Male) | Population(Female) | Total Population |
---|---|---|---|
Under 5 years | 430 | 476 | 906 |
5 to 9 years | 549 | 465 | 1,014 |
10 to 14 years | 474 | 423 | 897 |
15 to 19 years | 455 | 453 | 908 |
20 to 24 years | 407 | 335 | 742 |
25 to 29 years | 418 | 462 | 880 |
30 to 34 years | 456 | 371 | 827 |
35 to 39 years | 412 | 352 | 764 |
40 to 44 years | 387 | 404 | 791 |
45 to 49 years | 372 | 343 | 715 |
50 to 54 years | 434 | 361 | 795 |
55 to 59 years | 496 | 484 | 980 |
60 to 64 years | 530 | 521 | 1,051 |
65 to 69 years | 452 | 399 | 851 |
70 to 74 years | 290 | 338 | 628 |
75 to 79 years | 186 | 169 | 355 |
80 to 84 years | 126 | 263 | 389 |
85 years and over | 232 | 414 | 646 |
Things to know
What is the population of O Brien County, IA under 18?
O Brien County's population under the age of 18 is 3,405, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 24.08% of the total resident population of O Brien County, IA.
What is the aging population in O Brien County, IA?
O Brien County's population aged 65 years and above was 2,869. As per the U.S. Census Bureau's American Community Survey, this population is 20.29% of the entire population.
References
- U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates