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O'Fallon, IL Population by Age

The median age in O'Fallon, IL is 37.6, as per 2021 ACS 5-Year Estimates. Of the total population, 23.53% were under the age of 15, 15.85% aged 15 to 29, 45.68% aged 30 to 64, 12.52% aged 65 to 84, and 2.43% were 85 years of age and older.
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By Neilsberg Research
Updated Sep 17, 2023

O'Fallon, IL population age distribution

A complete breakdown of O'Fallon'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 2,640 8.26%
5 to 9 years 2,406 7.53%
10 to 14 years 2,475 7.74%
15 to 19 years 1,972 6.17%
20 to 24 years 1,238 3.87%
25 to 29 years 1,855 5.8%
30 to 34 years 2,279 7.13%
35 to 39 years 2,537 7.94%
40 to 44 years 2,061 6.45%
45 to 49 years 2,153 6.74%
50 to 54 years 2,301 7.2%
55 to 59 years 1,542 4.82%
60 to 64 years 1,727 5.4%
65 to 69 years 1,386 4.34%
70 to 74 years 1,119 3.5%
75 to 79 years 1,016 3.18%
80 to 84 years 480 1.5%
85 years and over 776 2.43%
Exploring O'Fallon's Diversity? Request Customized Data Now!

TABLE OF CONTENTS

O'Fallon, IL population by age group

Key stats
10,731
Population under 25 years
8,732
Population aged 25-44
7,723
Population aged 45-64
4,777
Population aged 65+

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

The graph shows O'Fallon'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
O'Fallon, IL population by age group. The largest age group was 0-4 years with a poulation of 2,640 (8.26% of the total population). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

The largest age group in O'Fallon, IL was for the group of age 0-4 years with a population of 2,640 (8.26%), according to the 2021 American Community Survey.

At the same time, the smallest age group in O'Fallon, IL was the 80-84 years with a population of 480 (1.50%).

O'Fallon, IL population by age cohort

To better understand the age distribution of O'Fallon, IL'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 O'Fallon'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.
O'Fallon, IL 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 18,259 (57.13% 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 8,927 27.93%
18 to 64 years 18,259 57.13%
85 years and over 4,777 14.95%
Exploring O'Fallon's Diversity? Request Customized Data Now!

Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:

  • O'Fallon's population under 18 was 27.93%, compared to the 22.51% nationwide.
  • O'Fallon's working population (between 18 and 64) was 57.13%, compared to 61.45% nationwide.
  • O'Fallon's elderly or the senior population (over 65 age) was 14.95% as compared to 16.04% nationwide.

O'Fallon, IL population pyramid

Population pyramid for O'Fallon, IL 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'Fallon's population pyramid:

  • Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for O'Fallon, IL, is 38.2.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for O'Fallon, IL, is 24.3.
  • Total dependency ratio for O'Fallon, IL is 62.5.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for O'Fallon, IL is 4.1.
The graph shows O'Fallon'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.
O'Fallon, IL population pyramid i.e. O'Fallon population distrubution across age and gender. Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Here's the O'Fallon, IL's male and female population across different age groups:

Age Group Population(Male) Population(Female) Total Population
Under 5 years 1,284 1,356 2,640
5 to 9 years 1,081 1,325 2,406
10 to 14 years 1,198 1,277 2,475
15 to 19 years 947 1,025 1,972
20 to 24 years 736 502 1,238
25 to 29 years 868 987 1,855
30 to 34 years 1,278 1,001 2,279
35 to 39 years 1,139 1,398 2,537
40 to 44 years 1,014 1,047 2,061
45 to 49 years 1,047 1,106 2,153
50 to 54 years 1,123 1,178 2,301
55 to 59 years 707 835 1,542
60 to 64 years 892 835 1,727
65 to 69 years 626 760 1,386
70 to 74 years 501 618 1,119
75 to 79 years 366 650 1,016
80 to 84 years 257 223 480
85 years and over 309 467 776
Exploring O'Fallon's Diversity? Request Customized Data Now!

Things to know

What is the population of O'Fallon, IL under 18?

O'Fallon's population under the age of 18 is 8,927, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 27.93% of the total resident population of O'Fallon, IL.

What is the aging population in O'Fallon, IL?

O'Fallon's population aged 65 years and above was 4,777. As per the U.S. Census Bureau's American Community Survey, this population is 14.95% of the entire population.

References

Datasets

Explore datasets by year of publication.
2023
O'Fallon, IL Age Group Population Dataset: A complete breakdown of O'Fallon 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 O'Fallon 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 O'Fallon. The dataset can be utilized to understand the population distribution of O'Fallon by age. For example, using this dataset, we can identify the largest age group in O'Fallon.

Key observations

The largest age group in O'Fallon, IL was for the group of age 0-4 years with a population of 2,640 (8.26%), according to the 2021 American Community Survey. At the same time, the smallest age group in O'Fallon, IL was the 80-84 years with a population of 480 (1.50%). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

O'Fallon 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 O'Fallon is shown in this column.
  • % of Total Population: This column displays the population of each age group as a proportion of O'Fallon 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 O'Fallon Population by Age. You can refer the same here

O'Fallon, IL Age Cohorts Dataset: Children, Working Adults, and Seniors in O'Fallon - 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 O'Fallon 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 O'Fallon. 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.

O'Fallon 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 O'Fallon population analysis. Total expected values are 3 groups ( Children, Working Population and Senior Population).
  • Population: The population for the age cohort in O'Fallon is shown in the following column.
  • Percent of Total Population: The population as a percent of total population of the O'Fallon 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 O'Fallon Population by Age. You can refer the same here

O'Fallon, IL 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 O'Fallon, IL population pyramid, which represents the O'Fallon 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 O'Fallon, IL, is 38.2.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for O'Fallon, IL, is 24.3.
  • Total dependency ratio for O'Fallon, IL is 62.5.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for O'Fallon, IL is 4.1.

O'Fallon 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 O'Fallon population analysis. Total expected values are 18 and are define above in the age groups section.
  • Population (Male): The male population in the O'Fallon for the selected age group is shown in the following column.
  • Population (Female): The female population in the O'Fallon for the selected age group is shown in the following column.
  • Total Population: The total population of the O'Fallon 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 O'Fallon 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.

Explore related topics

O''Fallon, IL Demographics O''Fallon, IL Population

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Neilsberg Research
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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