Data / Rankings / Population under 18 / Counties in Massachusetts

Counties in Massachusetts by population under 18

Hampden County had the highest population under 18 of 14 counties in 2018, at 21.5%. Barnstable County had the lowest, at 14.7%. The median was 19.5% and the figure for Massachusetts was 19.8%. Source: the U.S. Census Bureau.

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Highest21.5Hampden County
Lowest14.7Barnstable County
Median19.514 counties
Massachusetts19.8History

Map of counties, 2018

Barnstable County: 14.7 %Berkshire County: 17.4 %Bristol County: 20.5 %Dukes County: 16.2 %Essex County: 21.2 %Franklin County: 17.6 %Hampden County: 21.5 %Hampshire County: 15 %Middlesex County: 19.8 %Nantucket County: 19.3 %Norfolk County: 20.8 %Plymouth County: 21.4 %Suffolk County: 16.5 %Worcester County: 21.1 %
  • Under 16
  • 16 to 18
  • 18 to 20
  • 20 to 21
  • 21 and over
%, 2018. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2018

Hampden County: 21.5 %Hampden County21.5Plymouth County: 21.4 %Plymouth County21.4Essex County: 21.2 %Essex County21.2Worcester County: 21.1 %Worcester County21.1Norfolk County: 20.8 %Norfolk County20.8Bristol County: 20.5 %Bristol County20.5Middlesex County: 19.8 %Middlesex County19.8Nantucket County: 19.3 %Nantucket County19.3Franklin County: 17.6 %Franklin County17.6Berkshire County: 17.4 %Berkshire County17.4Suffolk County: 16.5 %Suffolk County16.5Dukes County: 16.2 %Dukes County16.2Hampshire County: 15 %Hampshire County15Barnstable County: 14.7 %Barnstable County14.7Hampden County: 21.5 %Hampden County21.5Plymouth County: 21.4 %Plymouth County21.4Essex County: 21.2 %Essex County21.2Worcester County: 21.1 %Worcester County21.1Norfolk County: 20.8 %Norfolk County20.8Bristol County: 20.5 %Bristol County20.5Middlesex County: 19.8 %Middlesex County19.8Nantucket County: 19.3 %Nantucket County19.3Franklin County: 17.6 %Franklin County17.6Berkshire County: 17.4 %Berkshire County17.4Suffolk County: 16.5 %Suffolk County16.5Dukes County: 16.2 %Dukes County16.2Hampshire County: 15 %Hampshire County15Barnstable County: 14.7 %Barnstable County14.7
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2018 (%)Change on 2017
1Hampden County21.5-0.2 pts
2Plymouth County21.4-0.3 pts
3Essex County21.2-0.2 pts
4Worcester County21.1-0.2 pts
5Norfolk County20.8-0.2 pts
6Bristol County20.5-0.1 pts
7Middlesex County19.8-0.2 pts
8Nantucket County19.3-0.1 pts
9Franklin County17.6-0.2 pts
10Berkshire County17.4-0.1 pts
11Suffolk County16.5-0.3 pts
12Dukes County16.2-0.3 pts
13Hampshire County15-0.2 pts
14Barnstable County14.7-0.3 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

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

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 Massachusetts 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 Massachusetts 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/massachusetts-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 Massachusetts 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/massachusetts-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 Massachusetts 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/massachusetts-counties?period=2018 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_massachusetts_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 Massachusetts 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/massachusetts-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 Massachusetts 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/massachusetts-counties?period=2018
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/massachusetts-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  -
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Rank Counties in Massachusetts by population under 18 using official data, and cite the source.
rank_places {"indicator":"population_0_17_share","level":"province","within":"Massachusetts","limit":10}
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Questions

Which county has the highest population under 18?

Hampden County, with 21.5% in 2018, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Barnstable County, with 14.7% 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.

Population under 18: other rankings

Counties in Massachusetts: more rankings