Fairfax County, VA Population by Age

The median age in Fairfax County, VA is 38.3, as per 2021 ACS 5-Year Estimates. Of the total population, 19.48% were under the age of 15, 18.69% aged 15 to 29, 48.21% aged 30 to 64, 12.24% aged 65 to 84, and 1.38% were 85 years of age and older.
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Updated Sep 17, 2023

Fairfax County, VA population age distribution

A complete breakdown of Fairfax 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 71,509 6.24%
5 to 9 years 74,307 6.48%
10 to 14 years 77,539 6.76%
15 to 19 years 74,130 6.46%
20 to 24 years 67,543 5.89%
25 to 29 years 72,647 6.33%
30 to 34 years 77,816 6.79%
35 to 39 years 87,469 7.63%
40 to 44 years 79,212 6.91%
45 to 49 years 82,033 7.15%
50 to 54 years 80,091 6.98%
55 to 59 years 77,137 6.73%
60 to 64 years 69,178 6.03%
65 to 69 years 53,542 4.67%
70 to 74 years 42,239 3.68%
75 to 79 years 27,701 2.42%
80 to 84 years 16,930 1.48%
85 years and over 15,802 1.38%
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Fairfax County, VA population by age group

Key stats
365,028
Population under 25 years
317,144
Population aged 25-44
308,439
Population aged 45-64
156,214
Population aged 65+

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

The graph shows Fairfax 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
Fairfax County, VA population by age group. The largest age group was 35-39 years with a poulation of 87,469 (7.63% of the total population). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

The largest age group in Fairfax County, VA was for the group of age 35-39 years with a population of 87,469 (7.63%), according to the 2021 American Community Survey.

At the same time, the smallest age group in Fairfax County, VA was the 85+ years with a population of 15,802 (1.38%).

Fairfax County, VA population by age cohort

To better understand the age distribution of Fairfax County, VA'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 Fairfax 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.
Fairfax County, VA 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 720,678 (62.84% 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 269,933 23.54%
18 to 64 years 720,678 62.84%
85 years and over 156,214 13.62%
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Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:

  • Fairfax County's population under 18 was 23.54%, compared to the 22.51% nationwide.
  • Fairfax County's working population (between 18 and 64) was 62.84%, compared to 61.45% nationwide.
  • Fairfax County's elderly or the senior population (over 65 age) was 13.62% as compared to 16.04% nationwide.

Fairfax County, VA population pyramid

Population pyramid for Fairfax County, VA 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 Fairfax County's population pyramid:

  • Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Fairfax County, VA, is 29.1.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Fairfax County, VA, is 20.4.
  • Total dependency ratio for Fairfax County, VA is 49.5.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for Fairfax County, VA is 4.9.
The graph shows Fairfax 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.
Fairfax County, VA population pyramid i.e. Fairfax County population distrubution across age and gender. Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

Here's the Fairfax County, VA's male and female population across different age groups:

Age Group Population(Male) Population(Female) Total Population
Under 5 years 36,664 34,845 71,509
5 to 9 years 38,859 35,448 74,307
10 to 14 years 39,207 38,332 77,539
15 to 19 years 38,108 36,022 74,130
20 to 24 years 34,037 33,506 67,543
25 to 29 years 37,440 35,207 72,647
30 to 34 years 39,566 38,250 77,816
35 to 39 years 42,863 44,606 87,469
40 to 44 years 40,172 39,040 79,212
45 to 49 years 40,637 41,396 82,033
50 to 54 years 39,685 40,406 80,091
55 to 59 years 38,008 39,129 77,137
60 to 64 years 34,754 34,424 69,178
65 to 69 years 25,667 27,875 53,542
70 to 74 years 20,127 22,112 42,239
75 to 79 years 13,252 14,449 27,701
80 to 84 years 7,248 9,682 16,930
85 years and over 5,896 9,906 15,802
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Things to know

What is the population of Fairfax County, VA under 18?

Fairfax County's population under the age of 18 is 269,933, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 23.54% of the total resident population of Fairfax County, VA.

What is the aging population in Fairfax County, VA?

Fairfax County's population aged 65 years and above was 156,214. As per the U.S. Census Bureau's American Community Survey, this population is 13.62% of the entire population.

References

Datasets

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

Key observations

The largest age group in Fairfax County, VA was for the group of age 35-39 years with a population of 87,469 (7.63%), according to the 2021 American Community Survey. At the same time, the smallest age group in Fairfax County, VA was the 85+ years with a population of 15,802 (1.38%). Source: U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates.

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

Fairfax County, VA Age Cohorts Dataset: Children, Working Adults, and Seniors in Fairfax 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 Fairfax 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 Fairfax 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.

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

Fairfax County, VA 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 Fairfax County, VA population pyramid, which represents the Fairfax 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 Fairfax County, VA, is 29.1.
  • Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Fairfax County, VA, is 20.4.
  • Total dependency ratio for Fairfax County, VA is 49.5.
  • Potential support ratio, which is the number of youth (working age population) per elderly, for Fairfax County, VA is 4.9.

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