Boulder County, CO Population by Age

The median age in Boulder County, CO is 37.2, as per 2021 ACS 5-Year Estimates. Of the total population, 15.25% were under the age of 15, 25.31% aged 15 to 29, 44.76% aged 30 to 64, 12.94% aged 65 to 84, and 1.74% were 85 years of age and older.
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Updated Sep 17, 2023

Boulder County, CO population age distribution

A complete breakdown of Boulder 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 14,030 4.27%
5 to 9 years 17,207 5.23%
10 to 14 years 18,877 5.74%
15 to 19 years 26,188 7.97%
20 to 24 years 32,981 10.03%
25 to 29 years 24,032 7.31%
30 to 34 years 21,624 6.58%
35 to 39 years 21,068 6.41%
40 to 44 years 20,665 6.29%
45 to 49 years 21,586 6.57%
50 to 54 years 20,767 6.32%
55 to 59 years 21,361 6.5%
60 to 64 years 20,053 6.1%
65 to 69 years 17,075 5.19%
70 to 74 years 13,492 4.1%
75 to 79 years 7,381 2.25%
80 to 84 years 4,601 1.4%
85 years and over 5,725 1.74%
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Boulder County, CO population by age group

Key stats
109,283
Population under 25 years
87,389
Population aged 25-44
83,767
Population aged 45-64
48,274
Population aged 65+

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

The graph shows Boulder 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
Boulder County, CO population by age group. The largest age group was 20-24 years with a poulation of 32,981 (10.03% of the total population). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

The largest age group in Boulder County, CO was for the group of age 20-24 years with a population of 32,981 (10.03%), according to the 2021 American Community Survey.

At the same time, the smallest age group in Boulder County, CO was the 80-84 years with a population of 4,601 (1.40%).

Boulder County, CO population by age cohort

To better understand the age distribution of Boulder County, CO'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 Boulder 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.
Boulder County, CO 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 218,304 (66.41% 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 62,135 18.9%
18 to 64 years 218,304 66.41%
85 years and over 48,274 14.69%
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Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:

  • Boulder County's population under 18 was 18.90%, compared to the 22.51% nationwide.
  • Boulder County's working population (between 18 and 64) was 66.41%, compared to 61.45% nationwide.
  • Boulder County's elderly or the senior population (over 65 age) was 14.69% as compared to 16.04% nationwide.

Boulder County, CO population pyramid

Population pyramid for Boulder County, CO 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 Boulder County's population pyramid:

  • Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Boulder County, CO, is 21.8.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Boulder County, CO, is 21.0.
  • Total dependency ratio for Boulder County, CO is 42.7.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for Boulder County, CO is 4.8.
The graph shows Boulder 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.
Boulder County, CO population pyramid i.e. Boulder County population distrubution across age and gender. Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Here's the Boulder County, CO's male and female population across different age groups:

Age Group Population(Male) Population(Female) Total Population
Under 5 years 7,137 6,893 14,030
5 to 9 years 8,765 8,442 17,207
10 to 14 years 9,707 9,170 18,877
15 to 19 years 13,228 12,960 26,188
20 to 24 years 17,417 15,564 32,981
25 to 29 years 12,983 11,049 24,032
30 to 34 years 11,671 9,953 21,624
35 to 39 years 11,128 9,940 21,068
40 to 44 years 10,058 10,607 20,665
45 to 49 years 10,918 10,668 21,586
50 to 54 years 10,386 10,381 20,767
55 to 59 years 10,574 10,787 21,361
60 to 64 years 9,904 10,149 20,053
65 to 69 years 8,612 8,463 17,075
70 to 74 years 6,145 7,347 13,492
75 to 79 years 3,423 3,958 7,381
80 to 84 years 1,911 2,690 4,601
85 years and over 2,173 3,552 5,725
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Things to know

What is the population of Boulder County, CO under 18?

Boulder County's population under the age of 18 is 62,135, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 18.90% of the total resident population of Boulder County, CO.

What is the aging population in Boulder County, CO?

Boulder County's population aged 65 years and above was 48,274. As per the U.S. Census Bureau's American Community Survey, this population is 14.69% of the entire population.

References

Datasets

Boulder County, CO Age Group Population Dataset: A complete breakdown of Boulder County age demographics from 0 to 85 years, distributed across 18 age groups
ACS
Free
Neilsberg
CSV, JSON
2017-2021
CC BY 4.0
About this dataset

Context

The dataset tabulates the Boulder 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 Boulder County. The dataset can be utilized to understand the population distribution of Boulder County by age. For example, using this dataset, we can identify the largest age group in Boulder County.

Key observations

The largest age group in Boulder County, CO was for the group of age 20-24 years with a population of 32,981 (10.03%), according to the 2021 American Community Survey. At the same time, the smallest age group in Boulder County, CO was the 80-84 years with a population of 4,601 (1.40%). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

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

Boulder County, CO Age Cohorts Dataset: Children, Working Adults, and Seniors in Boulder County - Population and Percentage Analysis
ACS
Free
Neilsberg
CSV, JSON
2017-2021
CC BY 4.0
About this dataset

Context

The dataset tabulates the Boulder 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 Boulder 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.

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

Boulder County, CO Population Pyramid Dataset: Age Groups, Male and Female Population, and Total Population for Demographics Analysis
ACS
Free
Neilsberg
CSV, JSON
2017-2021
CC BY 4.0
About this dataset

Context

The dataset tabulates the data for the Boulder County, CO population pyramid, which represents the Boulder 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 Boulder County, CO, is 21.8.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Boulder County, CO, is 21.0.
  • Total dependency ratio for Boulder County, CO is 42.7.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for Boulder County, CO is 4.8.

Boulder 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 Boulder County population analysis. Total expected values are 18 and are define above in the age groups section.
  • Population (Male): The male population in the Boulder County for the selected age group is shown in the following column.
  • Population (Female): The female population in the Boulder County for the selected age group is shown in the following column.
  • Total Population: The total population of the Boulder 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 Boulder County Population by Age. You can refer the same here

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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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