Pima County, AZ population age distribution
A complete breakdown of Pima 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 | 55,710 | 5.38% |
5 to 9 years | 59,948 | 5.79% |
10 to 14 years | 62,351 | 6.02% |
15 to 19 years | 69,312 | 6.7% |
20 to 24 years | 88,454 | 8.55% |
25 to 29 years | 71,152 | 6.87% |
30 to 34 years | 61,385 | 5.93% |
35 to 39 years | 62,891 | 6.08% |
40 to 44 years | 57,300 | 5.54% |
45 to 49 years | 56,635 | 5.47% |
50 to 54 years | 56,694 | 5.48% |
55 to 59 years | 62,735 | 6.06% |
60 to 64 years | 65,528 | 6.33% |
65 to 69 years | 64,551 | 6.24% |
70 to 74 years | 53,987 | 5.22% |
75 to 79 years | 39,794 | 3.84% |
80 to 84 years | 24,072 | 2.33% |
85 years and over | 22,564 | 2.18% |
TABLE OF CONTENTS
Pima County, AZ population by age group
Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

The largest age group in Pima County, AZ was for the group of age 20-24 years with a population of 88,454 (8.55%), according to the 2021 American Community Survey.
At the same time, the smallest age group in Pima County, AZ was the 85+ years with a population of 22,564 (2.18%).
Pima County, AZ population by age cohort
To better understand the age distribution of Pima County, AZ'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 | 215,628 | 20.83% |
18 to 64 years | 614,467 | 59.37% |
85 years and over | 204,968 | 19.8% |
Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:
- Pima County's population under 18 was 20.83%, compared to the 22.51% nationwide.
- Pima County's working population (between 18 and 64) was 59.37%, compared to 61.45% nationwide.
- Pima County's elderly or the senior population (over 65 age) was 19.80% as compared to 16.04% nationwide.
Pima County, AZ population pyramid
Population pyramid for Pima County, AZ 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 Pima County's population pyramid:
- Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Pima County, AZ, is 27.3.
- Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Pima County, AZ, is 31.4.
- Total dependency ratio for Pima County, AZ is 58.7.
- Potential support ratio, which is the number of youth (working age population) per elderly, for Pima County, AZ is 3.2.

Here's the Pima County, AZ's male and female population across different age groups:
Age Group | Population(Male) | Population(Female) | Total Population |
---|---|---|---|
Under 5 years | 28,436 | 27,274 | 55,710 |
5 to 9 years | 29,952 | 29,996 | 59,948 |
10 to 14 years | 32,615 | 29,736 | 62,351 |
15 to 19 years | 35,107 | 34,205 | 69,312 |
20 to 24 years | 44,901 | 43,553 | 88,454 |
25 to 29 years | 37,002 | 34,150 | 71,152 |
30 to 34 years | 32,064 | 29,321 | 61,385 |
35 to 39 years | 31,882 | 31,009 | 62,891 |
40 to 44 years | 28,804 | 28,496 | 57,300 |
45 to 49 years | 28,132 | 28,503 | 56,635 |
50 to 54 years | 27,924 | 28,770 | 56,694 |
55 to 59 years | 30,975 | 31,760 | 62,735 |
60 to 64 years | 30,221 | 35,307 | 65,528 |
65 to 69 years | 29,690 | 34,861 | 64,551 |
70 to 74 years | 25,640 | 28,347 | 53,987 |
75 to 79 years | 18,288 | 21,506 | 39,794 |
80 to 84 years | 11,017 | 13,055 | 24,072 |
85 years and over | 9,069 | 13,495 | 22,564 |
Things to know
What is the population of Pima County, AZ under 18?
Pima County's population under the age of 18 is 215,628, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 20.83% of the total resident population of Pima County, AZ.
What is the aging population in Pima County, AZ?
Pima County's population aged 65 years and above was 204,968. As per the U.S. Census Bureau's American Community Survey, this population is 19.80% of the entire population.
References
- U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates