St. Louis County, MO Population by Age

The median age in St. Louis County, MO is 40.3, as per 2021 ACS 5-Year Estimates. Of the total population, 18.28% were under the age of 15, 18.69% aged 15 to 29, 45.00% aged 30 to 64, 15.55% aged 65 to 84, and 2.49% were 85 years of age and older.
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Updated Sep 17, 2023

St. Louis County, MO population age distribution

A complete breakdown of St. Louis 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 58,253 5.81%
5 to 9 years 59,845 5.97%
10 to 14 years 65,102 6.5%
15 to 19 years 63,586 6.35%
20 to 24 years 59,670 5.96%
25 to 29 years 63,984 6.39%
30 to 34 years 63,337 6.32%
35 to 39 years 63,744 6.36%
40 to 44 years 59,516 5.94%
45 to 49 years 59,548 5.94%
50 to 54 years 63,493 6.34%
55 to 59 years 70,554 7.04%
60 to 64 years 70,675 7.05%
65 to 69 years 58,914 5.88%
70 to 74 years 45,574 4.55%
75 to 79 years 29,789 2.97%
80 to 84 years 21,497 2.15%
85 years and over 24,901 2.49%
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St. Louis County, MO population by age group

Key stats
306,456
Population under 25 years
250,581
Population aged 25-44
264,270
Population aged 45-64
180,675
Population aged 65+

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

The graph shows St. Louis 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
St. Louis County, MO population by age group. The largest age group was 60-64 years with a poulation of 70,675 (7.05% of the total population). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

The largest age group in St. Louis County, MO was for the group of age 60-64 years with a population of 70,675 (7.05%), according to the 2021 American Community Survey.

At the same time, the smallest age group in St. Louis County, MO was the 80-84 years with a population of 21,497 (2.15%).

St. Louis County, MO population by age cohort

To better understand the age distribution of St. Louis County, MO'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 St. Louis 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.
St. Louis County, MO 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 598,459 (59.73% 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 222,848 22.24%
18 to 64 years 598,459 59.73%
85 years and over 180,675 18.03%
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Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:

  • St. Louis County's population under 18 was 22.24%, compared to the 22.51% nationwide.
  • St. Louis County's working population (between 18 and 64) was 59.73%, compared to 61.45% nationwide.
  • St. Louis County's elderly or the senior population (over 65 age) was 18.03% as compared to 16.04% nationwide.

St. Louis County, MO population pyramid

Population pyramid for St. Louis County, MO 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 St. Louis County's population pyramid:

  • Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for St. Louis County, MO, is 28.7.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for St. Louis County, MO, is 28.3.
  • Total dependency ratio for St. Louis County, MO is 57.0.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for St. Louis County, MO is 3.5.
The graph shows St. Louis 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.
St. Louis County, MO population pyramid i.e. St. Louis County population distrubution across age and gender. Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Here's the St. Louis County, MO's male and female population across different age groups:

Age Group Population(Male) Population(Female) Total Population
Under 5 years 29,791 28,462 58,253
5 to 9 years 31,470 28,375 59,845
10 to 14 years 32,490 32,612 65,102
15 to 19 years 32,343 31,243 63,586
20 to 24 years 29,635 30,035 59,670
25 to 29 years 31,305 32,679 63,984
30 to 34 years 30,500 32,837 63,337
35 to 39 years 31,052 32,692 63,744
40 to 44 years 28,221 31,295 59,516
45 to 49 years 28,154 31,394 59,548
50 to 54 years 30,131 33,362 63,493
55 to 59 years 33,522 37,032 70,554
60 to 64 years 33,252 37,423 70,675
65 to 69 years 27,098 31,816 58,914
70 to 74 years 20,038 25,536 45,574
75 to 79 years 12,934 16,855 29,789
80 to 84 years 8,277 13,220 21,497
85 years and over 8,405 16,496 24,901
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Things to know

What is the population of St. Louis County, MO under 18?

St. Louis County's population under the age of 18 is 222,848, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 22.24% of the total resident population of St. Louis County, MO.

What is the aging population in St. Louis County, MO?

St. Louis County's population aged 65 years and above was 180,675. As per the U.S. Census Bureau's American Community Survey, this population is 18.03% of the entire population.

References

Datasets

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

Key observations

The largest age group in St. Louis County, MO was for the group of age 60-64 years with a population of 70,675 (7.05%), according to the 2021 American Community Survey. At the same time, the smallest age group in St. Louis County, MO was the 80-84 years with a population of 21,497 (2.15%). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

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

St. Louis County, MO Age Cohorts Dataset: Children, Working Adults, and Seniors in St. Louis 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 St. Louis 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 St. Louis 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.

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

St. Louis County, MO 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 St. Louis County, MO population pyramid, which represents the St. Louis 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 St. Louis County, MO, is 28.7.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for St. Louis County, MO, is 28.3.
  • Total dependency ratio for St. Louis County, MO is 57.0.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for St. Louis County, MO is 3.5.

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

About the author

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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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