Polk County, IA Population by Age

The median age in Polk County, IA is 35.9, as per 2021 ACS 5-Year Estimates. Of the total population, 20.85% were under the age of 15, 20.39% aged 15 to 29, 45.71% aged 30 to 64, 11.52% aged 65 to 84, and 1.52% were 85 years of age and older.
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Updated Sep 17, 2023

Polk County, IA population age distribution

A complete breakdown of Polk 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 33,634 6.88%
5 to 9 years 32,822 6.71%
10 to 14 years 35,495 7.26%
15 to 19 years 31,558 6.46%
20 to 24 years 30,565 6.25%
25 to 29 years 37,580 7.69%
30 to 34 years 36,992 7.57%
35 to 39 years 35,831 7.33%
40 to 44 years 32,623 6.67%
45 to 49 years 30,353 6.21%
50 to 54 years 29,877 6.11%
55 to 59 years 31,561 6.46%
60 to 64 years 26,244 5.37%
65 to 69 years 22,197 4.54%
70 to 74 years 17,122 3.5%
75 to 79 years 10,086 2.06%
80 to 84 years 6,893 1.41%
85 years and over 7,438 1.52%
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Polk County, IA population by age group

Key stats
164,074
Population under 25 years
143,026
Population aged 25-44
118,035
Population aged 45-64
63,736
Population aged 65+

Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

The graph shows Polk 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
Polk County, IA population by age group. The largest age group was 25-29 years with a poulation of 37,580 (7.69% of the total population). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

The largest age group in Polk County, IA was for the group of age 25-29 years with a population of 37,580 (7.69%), according to the 2021 American Community Survey.

At the same time, the smallest age group in Polk County, IA was the 80-84 years with a population of 6,893 (1.41%).

Polk County, IA population by age cohort

To better understand the age distribution of Polk 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
The pie chart shows Polk 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.
Polk County, IA population by age cohorts (Children: Under 18 years; Working population: 18-64 years; Senior population: 65 years or more). The largest age group was 18 - 64 years with a poulation of 303,308 (62.04% of the total population). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Here's the population for each of the three cohorts.

Age Group Population % of Total Population
Under 18 years 121,827 24.92%
18 to 64 years 303,308 62.04%
85 years and over 63,736 13.04%
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Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:

  • Polk County's population under 18 was 24.92%, compared to the 22.51% nationwide.
  • Polk County's working population (between 18 and 64) was 62.04%, compared to 61.45% nationwide.
  • Polk County's elderly or the senior population (over 65 age) was 13.04% as compared to 16.04% nationwide.

Polk County, IA population pyramid

Population pyramid for Polk 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 Polk County's population pyramid:

  • Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Polk County, IA, is 31.5.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Polk County, IA, is 19.7.
  • Total dependency ratio for Polk County, IA is 51.3.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for Polk County, IA is 5.1.
The graph shows Polk 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.
Polk County, IA population pyramid i.e. Polk County population distrubution across age and gender. Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Here's the Polk County, IA's male and female population across different age groups:

Age Group Population(Male) Population(Female) Total Population
Under 5 years 17,128 16,506 33,634
5 to 9 years 15,954 16,868 32,822
10 to 14 years 18,914 16,581 35,495
15 to 19 years 15,906 15,652 31,558
20 to 24 years 15,081 15,484 30,565
25 to 29 years 18,817 18,763 37,580
30 to 34 years 18,772 18,220 36,992
35 to 39 years 17,956 17,875 35,831
40 to 44 years 16,876 15,747 32,623
45 to 49 years 15,415 14,938 30,353
50 to 54 years 15,106 14,771 29,877
55 to 59 years 15,647 15,914 31,561
60 to 64 years 12,655 13,589 26,244
65 to 69 years 10,451 11,746 22,197
70 to 74 years 7,924 9,198 17,122
75 to 79 years 4,194 5,892 10,086
80 to 84 years 2,642 4,251 6,893
85 years and over 2,860 4,578 7,438
Exploring Polk County's Diversity? Request Customized Data Now!

Things to know

What is the population of Polk County, IA under 18?

Polk County's population under the age of 18 is 121,827, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 24.92% of the total resident population of Polk County, IA.

What is the aging population in Polk County, IA?

Polk County's population aged 65 years and above was 63,736. As per the U.S. Census Bureau's American Community Survey, this population is 13.04% of the entire population.

References

Datasets

Explore datasets by year of publication.
2023
Polk County, IA Age Group Population Dataset: A complete breakdown of Polk County age demographics from 0 to 85 years, distributed across 18 age groups
Last updated September 16, 2023
ACS
Free
Neilsberg
CSV, JSON
2017-2021
CC BY 4.0
About this dataset

Context

The dataset tabulates the Polk County population distribution across 18 age groups. It lists the population in each age group along with the percentage population relative of the total population for Polk County. The dataset can be utilized to understand the population distribution of Polk County by age. For example, using this dataset, we can identify the largest age group in Polk County.

Key observations

The largest age group in Polk County, IA was for the group of age 25-29 years with a population of 37,580 (7.69%), according to the 2021 American Community Survey. At the same time, the smallest age group in Polk County, IA was the 80-84 years with a population of 6,893 (1.41%). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Polk County population by age group

Content

When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Age groups:

  • Under 5 years
  • 5 to 9 years
  • 10 to 14 years
  • 15 to 19 years
  • 20 to 24 years
  • 25 to 29 years
  • 30 to 34 years
  • 35 to 39 years
  • 40 to 44 years
  • 45 to 49 years
  • 50 to 54 years
  • 55 to 59 years
  • 60 to 64 years
  • 65 to 69 years
  • 70 to 74 years
  • 75 to 79 years
  • 80 to 84 years
  • 85 years and over

Variables / Data Columns

  • Age Group: This column displays the age group in consideration
  • Population: The population for the specific age group in the Polk County is shown in this column.
  • % of Total Population: This column displays the population of each age group as a proportion of Polk County total population. Please note that the sum of all percentages may not equal one due to rounding of values.

Good to know

Margin of Error

Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.

Custom data

If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.

Inspiration

Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.

Recommended for further research

This dataset is a part of the main dataset for Polk County Population by Age. You can refer the same here

Polk County, IA Age Cohorts Dataset: Children, Working Adults, and Seniors in Polk County - Population and Percentage Analysis
Last updated September 16, 2023
ACS
Free
Neilsberg
CSV, JSON
2017-2021
CC BY 4.0
About this dataset

Context

The dataset tabulates the Polk County population by age cohorts (Children: Under 18 years; Working population: 18-64 years; Senior population: 65 years or more). It lists the population in each age cohort group along with its percentage relative to the total population of Polk County. The dataset can be utilized to understand the population distribution across children, working population and senior population for dependency ratio, housing requirements, ageing, migration patterns etc.

Key observations

The largest age group was $b3_v1 with a poulation of $b3_v2 ($b3_v3 of the total population). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Polk County population by age cohort

Content

When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Age cohorts:

  • Under 18 years
  • 18 to 64 years
  • 65 years and over

Variables / Data Columns

  • Age Group: This column displays the age cohort for the Polk County population analysis. Total expected values are 3 groups ( Children, Working Population and Senior Population).
  • Population: The population for the age cohort in Polk County is shown in the following column.
  • Percent of Total Population: The population as a percent of total population of the Polk County is shown in the following column.

Good to know

Margin of Error

Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.

Custom data

If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.

Inspiration

Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.

Recommended for further research

This dataset is a part of the main dataset for Polk County Population by Age. You can refer the same here

Polk County, IA Population Pyramid Dataset: Age Groups, Male and Female Population, and Total Population for Demographics Analysis
Last updated September 16, 2023
ACS
Free
Neilsberg
CSV, JSON
2017-2021
CC BY 4.0
About this dataset

Context

The dataset tabulates the data for the Polk County, IA population pyramid, which represents the Polk County population distribution across age and gender, using estimates from the U.S. Census Bureau American Community Survey 5-Year estimates. It lists the male and female population for each age group, along with the total population for those age groups. Higher numbers at the bottom of the table suggest population growth, whereas higher numbers at the top indicate declining birth rates. Furthermore, the dataset can be utilized to understand the youth dependency ratio, old-age dependency ratio, total dependency ratio, and potential support ratio.

Key observations

  • Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Polk County, IA, is 31.5.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Polk County, IA, is 19.7.
  • Total dependency ratio for Polk County, IA is 51.3.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for Polk County, IA is 5.1.

Polk County population pyramid

Content

When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Age groups:

  • Under 5 years
  • 5 to 9 years
  • 10 to 14 years
  • 15 to 19 years
  • 20 to 24 years
  • 25 to 29 years
  • 30 to 34 years
  • 35 to 39 years
  • 40 to 44 years
  • 45 to 49 years
  • 50 to 54 years
  • 55 to 59 years
  • 60 to 64 years
  • 65 to 69 years
  • 70 to 74 years
  • 75 to 79 years
  • 80 to 84 years
  • 85 years and over

Variables / Data Columns

  • Age Group: This column displays the age group for the Polk County population analysis. Total expected values are 18 and are define above in the age groups section.
  • Population (Male): The male population in the Polk County for the selected age group is shown in the following column.
  • Population (Female): The female population in the Polk County for the selected age group is shown in the following column.
  • Total Population: The total population of the Polk County for the selected age group is shown in the following column.

Good to know

Margin of Error

Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.

Custom data

If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.

Inspiration

Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.

Recommended for further research

This dataset is a part of the main dataset for Polk County Population by Age. You can refer the same here

If you're looking for datasets from another year, please feel free to contact us at research@neilsberg.com and we'll be happy to assist you further.

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Neilsberg Research team are data scientists with expertise in processing, analysis and visualization of big data helping small businesses make right decisions.

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