Counties in Utah by population under 18
Morgan County had the highest population under 18 of 29 counties in 2021, at 34.2%. Grand County had the lowest, at 20.6%. The median was 28.9% and the figure for Utah was 28.4%. Source: the U.S. Census Bureau.
Map of counties, 2021
- Under 24
- 24 to 27
- 27 to 29
- 29 to 32
- 32 and over
All counties, 2021
Full ranking
| Rank | Counties | 2021 (%) | Change on 2020 |
|---|---|---|---|
| 1 | Morgan County | 34.2 | -0.5 pts |
| 2 | Juab County | 34.1 | -0.3 pts |
| 3 | Uintah County | 32.5 | -0.5 pts |
| 4 | Tooele County | 32.4 | -0.5 pts |
| 5 | Duchesne County | 32.3 | -0.5 pts |
| 6 | Utah County | 32.1 | -0.5 pts |
| 7 | Davis County | 31.2 | -0.7 pts |
| 8 | Box Elder County | 31 | -0.4 pts |
| 9 | Millard County | 31 | -0.2 pts |
| 10 | Beaver County | 29.8 | -0.6 pts |
| 11 | Rich County | 29.6 | +0.1 pts |
| 12 | Sevier County | 29.4 | -0.5 pts |
| 13 | Wasatch County | 29.2 | -0.9 pts |
| 14 | Emery County | 28.9 | -0.2 pts |
| 15 | Cache County | 28.9 | -0.3 pts |
| 16 | San Juan County | 28.4 | -0.4 pts |
| 17 | Iron County | 27.8 | -0.5 pts |
| 18 | Sanpete County | 27.3 | -0.6 pts |
| 19 | Weber County | 27.2 | -0.5 pts |
| 20 | Washington County | 25.8 | -0.4 pts |
| 21 | Salt Lake County | 25.6 | -0.6 pts |
| 22 | Carbon County | 25.3 | -0.6 pts |
| 23 | Piute County | 24.3 | -0.3 pts |
| 24 | Summit County | 23.7 | -0.6 pts |
| 25 | Daggett County | 23.6 | -0.2 pts |
| 26 | Kane County | 22.9 | +0.2 pts |
| 27 | Garfield County | 22.9 | -0.5 pts |
| 28 | Wayne County | 22.4 | -0 pts |
| 29 | Grand County | 20.6 | -1 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 Utah 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 Utah 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/utah-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 Utah 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/utah-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 Utah 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/utah-counties?period=2021 (Accessed: 12 October 2026).
BibTeX
@misc{census_counties_in_utah_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 Utah 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/utah-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 Utah 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/utah-counties?period=2021
Y2 - 2026/10/12
N1 - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/utah-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 Utah by population under 18 using official data, and cite the source.
rank_places {"indicator":"population_0_17_share","level":"province","within":"Utah","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_0_17_share&level=province&within=Utah&limit=10Questions
Which county has the highest population under 18?
Morgan County, with 34.2% in 2021, according to the U.S. Census Bureau.
Which county has the lowest population under 18?
Grand County, with 20.6% 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.