Counties in Arizona by population under 18
Greenlee County had the highest population under 18 of 15 counties in 2021, at 27.9%. Yavapai County had the lowest, at 15.5%. The median was 23.3% and the figure for Arizona was 22.4%. Source: the U.S. Census Bureau.
Map of counties, 2021
- Under 19
- 19 to 21
- 21 to 24
- 24 to 26
- 26 and over
All counties, 2021
Full ranking
| Rank | Counties | 2021 (%) | Change on 2020 |
|---|---|---|---|
| 1 | Greenlee County | 27.9 | +0.1 pts |
| 2 | Graham County | 27.6 | -0.4 pts |
| 3 | Apache County | 26.1 | -0.3 pts |
| 4 | Santa Cruz County | 26.1 | -0.7 pts |
| 5 | Navajo County | 25.8 | -0.4 pts |
| 6 | Yuma County | 25.4 | -0.2 pts |
| 7 | Pinal County | 23.4 | -0.2 pts |
| 8 | Maricopa County | 23.3 | -0.4 pts |
| 9 | Cochise County | 20.8 | -0.3 pts |
| 10 | Coconino County | 20.1 | -0.1 pts |
| 11 | Pima County | 20.1 | -0.3 pts |
| 12 | Gila County | 19 | -0.4 pts |
| 13 | La Paz County | 18.6 | -0.1 pts |
| 14 | Mohave County | 16.7 | -0.1 pts |
| 15 | Yavapai County | 15.5 | -0.3 pts |
Other periods
About this ranking
Residents aged 0 to 17 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.
Uses the US age of majority. Not comparable with population_0_14_share, which stops at 14.
Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.
How to cite
U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.Citation styles
APA 7
U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (Counties in Arizona by population under 18, 2021) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html
MLA 9
Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Arizona by population under 18, 2021. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-under-18/arizona-counties?period=2021. Accessed 12 Oct. 2026.
Chicago (author-date)
U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Counties in Arizona by population under 18, 2021. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/population-under-18/arizona-counties?period=2021.
Harvard
U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Arizona by population under 18, 2021 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/arizona-counties?period=2021 (Accessed: 12 October 2026).
BibTeX
@misc{census_counties_in_arizona_by_2021,
author = {{U.S. Census Bureau}},
title = {{Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Arizona by population under 18, 2021}},
year = {2026},
howpublished = {Data set},
url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
urldate = {2026-10-12},
note = {Accessed via Invokely, https://invokely.ai/rankings/population-under-18/arizona-counties?period=2021. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}
RIS
TY - DATA
AU - U.S. Census Bureau
TI - Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Arizona by population under 18, 2021
PY - 2026
DA - 2026/06/25
PB - U.S. Census Bureau
DB - Invokely
UR - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2 - https://invokely.ai/rankings/population-under-18/arizona-counties?period=2021
Y2 - 2026/10/12
N1 - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/arizona-counties?period=2021.
N1 - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER -
Use this data in your AI agent
Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:
Rank Counties in Arizona by population under 18 using official data, and cite the source.
rank_places {"indicator":"population_0_17_share","level":"province","within":"Arizona","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_0_17_share&level=province&within=Arizona&limit=10Questions
Which county has the highest population under 18?
Greenlee County, with 27.9% in 2021, according to the U.S. Census Bureau.
Which county has the lowest population under 18?
Yavapai County, with 15.5% in 2021.
Where does this ranking come from?
Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Retrieved 2026-10-12.