Counties in Maryland by population under 18
Howard County had the highest population under 18 of 24 counties in 2018, at 24.6%. Kent County had the lowest, at 16.1%. The median was 21.9% and the figure for Maryland was 22.2%. Source: the U.S. Census Bureau.
Map of counties, 2018
- Under 19
- 19 to 22
- 22 to 24
- 24 and over
All counties, 2018
Full ranking
| Rank | Counties | 2018 (%) | Change on 2017 |
|---|---|---|---|
| 1 | Howard County | 24.6 | -0.2 pts |
| 2 | St. Mary's County | 24.4 | -0.2 pts |
| 3 | Charles County | 24.1 | -0.2 pts |
| 4 | Caroline County | 23.7 | +0.1 pts |
| 5 | Calvert County | 23.6 | -0.2 pts |
| 6 | Frederick County | 23.6 | -0.1 pts |
| 7 | Montgomery County | 23.2 | -0.1 pts |
| 8 | Cecil County | 22.7 | -0.2 pts |
| 9 | Anne Arundel County | 22.5 | -0 pts |
| 10 | Harford County | 22.4 | -0.2 pts |
| 11 | Prince George's County | 22.1 | -0.1 pts |
| 12 | Carroll County | 21.9 | -0.1 pts |
| 13 | Wicomico County | 21.9 | -0.1 pts |
| 14 | Washington County | 21.8 | -0.2 pts |
| 15 | Queen Anne's County | 21.8 | -0.1 pts |
| 16 | Baltimore County | 21.6 | -0 pts |
| 17 | Dorchester County | 21.1 | -0.1 pts |
| 18 | Baltimore city | 19.9 | -0.3 pts |
| 19 | Garrett County | 19.3 | -0.2 pts |
| 20 | Talbot County | 18.2 | -0.2 pts |
| 21 | Allegany County | 17.7 | -0.1 pts |
| 22 | Worcester County | 17.5 | -0.1 pts |
| 23 | Somerset County | 17.4 | -0.1 pts |
| 24 | Kent County | 16.1 | +0.1 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 Maryland by population under 18, 2018) [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 Maryland by population under 18, 2018. 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/maryland-counties?period=2018. 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 Maryland by population under 18, 2018. 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/maryland-counties?period=2018.
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 Maryland by population under 18, 2018 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/maryland-counties?period=2018 (Accessed: 12 October 2026).
BibTeX
@misc{census_counties_in_maryland_by_2018,
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 Maryland by population under 18, 2018}},
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/maryland-counties?period=2018. 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 Maryland by population under 18, 2018
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/maryland-counties?period=2018
Y2 - 2026/10/12
N1 - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/maryland-counties?period=2018.
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 Maryland by population under 18 using official data, and cite the source.
rank_places {"indicator":"population_0_17_share","level":"province","within":"Maryland","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_0_17_share&level=province&within=Maryland&limit=10Questions
Which county has the highest population under 18?
Howard County, with 24.6% in 2018, according to the U.S. Census Bureau.
Which county has the lowest population under 18?
Kent County, with 16.1% in 2018.
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.