Buchanan County, MO population age distribution
A complete breakdown of Buchanan 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 | 5,366 | 6.27% |
5 to 9 years | 5,417 | 6.33% |
10 to 14 years | 5,417 | 6.33% |
15 to 19 years | 5,329 | 6.23% |
20 to 24 years | 5,990 | 7% |
25 to 29 years | 5,650 | 6.6% |
30 to 34 years | 5,820 | 6.8% |
35 to 39 years | 5,785 | 6.76% |
40 to 44 years | 5,051 | 5.9% |
45 to 49 years | 4,802 | 5.61% |
50 to 54 years | 5,496 | 6.42% |
55 to 59 years | 5,771 | 6.75% |
60 to 64 years | 5,795 | 6.77% |
65 to 69 years | 4,692 | 5.48% |
70 to 74 years | 3,544 | 4.14% |
75 to 79 years | 2,446 | 2.86% |
80 to 84 years | 1,560 | 1.82% |
85 years and over | 1,614 | 1.89% |
TABLE OF CONTENTS
Buchanan County, MO population by age group
Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

The largest age group in Buchanan County, MO was for the group of age 20-24 years with a population of 5,990 (7.00%), according to the 2021 American Community Survey.
At the same time, the smallest age group in Buchanan County, MO was the 80-84 years with a population of 1,560 (1.82%).
Buchanan County, MO population by age cohort
To better understand the age distribution of Buchanan 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

Here's the population for each of the three cohorts.
Age Group | Population | % of Total Population |
---|---|---|
Under 18 years | 19,380 | 22.65% |
18 to 64 years | 52,309 | 61.15% |
85 years and over | 13,856 | 16.2% |
Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:
- Buchanan County's population under 18 was 22.65%, compared to the 22.51% nationwide.
- Buchanan County's working population (between 18 and 64) was 61.15%, compared to 61.45% nationwide.
- Buchanan County's elderly or the senior population (over 65 age) was 16.20% as compared to 16.04% nationwide.
Buchanan County, MO population pyramid
Population pyramid for Buchanan 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 Buchanan County's population pyramid:
- Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Buchanan County, MO, is 29.2.
- Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Buchanan County, MO, is 25.0.
- Total dependency ratio for Buchanan County, MO is 54.2.
- Potential support ratio, which is the number of youth (working age population) per elderly, for Buchanan County, MO is 4.0.

Here's the Buchanan County, MO's male and female population across different age groups:
Age Group | Population(Male) | Population(Female) | Total Population |
---|---|---|---|
Under 5 years | 2,780 | 2,586 | 5,366 |
5 to 9 years | 2,854 | 2,563 | 5,417 |
10 to 14 years | 2,676 | 2,741 | 5,417 |
15 to 19 years | 2,669 | 2,660 | 5,329 |
20 to 24 years | 3,271 | 2,719 | 5,990 |
25 to 29 years | 2,924 | 2,726 | 5,650 |
30 to 34 years | 3,013 | 2,807 | 5,820 |
35 to 39 years | 3,216 | 2,569 | 5,785 |
40 to 44 years | 2,776 | 2,275 | 5,051 |
45 to 49 years | 2,486 | 2,316 | 4,802 |
50 to 54 years | 2,827 | 2,669 | 5,496 |
55 to 59 years | 2,994 | 2,777 | 5,771 |
60 to 64 years | 2,806 | 2,989 | 5,795 |
65 to 69 years | 2,204 | 2,488 | 4,692 |
70 to 74 years | 1,638 | 1,906 | 3,544 |
75 to 79 years | 936 | 1,510 | 2,446 |
80 to 84 years | 705 | 855 | 1,560 |
85 years and over | 591 | 1,023 | 1,614 |
Things to know
What is the population of Buchanan County, MO under 18?
Buchanan County's population under the age of 18 is 19,380, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 22.65% of the total resident population of Buchanan County, MO.
What is the aging population in Buchanan County, MO?
Buchanan County's population aged 65 years and above was 13,856. As per the U.S. Census Bureau's American Community Survey, this population is 16.20% of the entire population.
References
- U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates