Data / Rankings / Population under 18 / US counties

US counties by population under 18

Kusilvak Census Area had the highest population under 18 of 3135 counties in 2019, at 40.7%. Sumter County had the lowest, at 7.1%. The median was 22% and the figure for the United States was 22.2%. Source: the U.S. Census Bureau.

Highest40.7Kusilvak Census Area
Lowest7.1Sumter County
Median223135 counties
United States22.2History

Top 40 counties, 2019

Kusilvak Census Area: 40.7 %Kusilvak Census Area40.7Todd County: 40.2 %Todd County40.2Buffalo County: 39.2 %Buffalo County39.2Oglala Lakota County: 37.2 %Oglala Lakota County37.2Loving County: 36.9 %Loving County36.9Corson County: 35.8 %Corson County35.8Northwest Arctic Borough: 35.7 %Northwest Arctic Borough35.7Bethel Census Area: 35.5 %Bethel Census Area35.5Morgan County: 35.3 %Morgan County35.3Sioux County: 35.2 %Sioux County35.2Ziebach County: 34.9 %Ziebach County34.9Gaines County: 34.4 %Gaines County34.4Thurston County: 34.3 %Thurston County34.3Juab County: 34.3 %Juab County34.3Adams County: 34.2 %Adams County34.2Jefferson County: 34.1 %Jefferson County34.1Benson County: 33.8 %Benson County33.8Rolette County: 33.7 %Rolette County33.7Big Horn County: 33.6 %Big Horn County33.6Uintah County: 33.4 %Uintah County33.4LaGrange County: 33.3 %LaGrange County33.3Tooele County: 33.2 %Tooele County33.2Utah County: 33.1 %Utah County33.1Nome Census Area: 33 %Nome Census Area33Jackson County: 32.7 %Jackson County32.7Bennett County: 32.6 %Bennett County32.6Davis County: 32.4 %Davis County32.4Dewey County: 32.4 %Dewey County32.4Duchesne County: 32.4 %Duchesne County32.4Menominee County: 32.3 %Menominee County32.3Mellette County: 32.2 %Mellette County32.2Franklin County: 32.1 %Franklin County32.1Hamlin County: 32.1 %Hamlin County32.1Box Elder County: 31.8 %Box Elder County31.8Franklin County: 31.7 %Franklin County31.7Cassia County: 31.4 %Cassia County31.4Adams County: 31.4 %Adams County31.4Dillingham Census Area: 31.3 %Dillingham Census Area31.3Glacier County: 31.2 %Glacier County31.2Millard County: 31.2 %Millard County31.2
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2019 (%)Change on 2018
1Kusilvak Census Area40.7+0.4 pts
2Todd County40.2-0.4 pts
3Buffalo County39.2-0 pts
4Oglala Lakota County37.2-0.6 pts
5Loving County36.9+8.6 pts
6Corson County35.8-0.8 pts
7Northwest Arctic Borough35.7+0.4 pts
8Bethel Census Area35.5-0.1 pts
9Morgan County35.3-0.3 pts
10Sioux County35.2-0.6 pts
11Ziebach County34.9-0.1 pts
12Gaines County34.4+0.2 pts
13Thurston County34.3-0.5 pts
14Juab County34.3-0.2 pts
15Adams County34.2+0.1 pts
16Jefferson County34.1-0.5 pts
17Benson County33.8-0.1 pts
18Rolette County33.7-0.4 pts
19Big Horn County33.6-0.1 pts
20Uintah County33.4-0.3 pts
21LaGrange County33.3-0.1 pts
22Tooele County33.2-0.4 pts
23Utah County33.1-0.4 pts
24Nome Census Area33-0.7 pts
25Jackson County32.7+1.3 pts
26Bennett County32.6-0.4 pts
27Davis County32.4-0.3 pts
28Dewey County32.4-0.7 pts
29Duchesne County32.4-0.4 pts
30Menominee County32.3-0.2 pts
31Mellette County32.2-0.3 pts
32Franklin County32.1-0.3 pts
33Hamlin County32.1+0.8 pts
34Box Elder County31.8-0.3 pts
35Franklin County31.7-0.5 pts
36Cassia County31.4-0.3 pts
37Adams County31.4-0.1 pts
38Dillingham Census Area31.30 pts
39Glacier County31.2+0.1 pts
40Millard County31.2+0.1 pts
41Zapata County31.1-0.4 pts
42Holmes County31-0.4 pts
43Bingham County30.9-0.3 pts
44Seward County30.9-0.5 pts
45Roosevelt County30.9-0.4 pts
46Ford County30.8-0.1 pts
47Wasatch County30.8-0.9 pts
48Jerome County30.7-0.2 pts
49King County30.7+1.9 pts
50Webb County30.7-0.7 pts
51Bailey County30.6-0.5 pts
52Beaver County30.6-0.1 pts
53Hidalgo County30.6-0.6 pts
54Andrews County30.6+0.1 pts
55Rich County30.5+0.4 pts
56Bonneville County30.4-0.3 pts
57Haskell County30.4+0.5 pts
58Starr County30.4-0.5 pts
59Deaf Smith County30.4-0.3 pts
60Power County30.3-0.7 pts
61Ochiltree County30.3-0.5 pts
62Colfax County30.3+0.2 pts
63Moore County30.3+0.1 pts
64Sevier County30.2-0.4 pts
65Long County30.20 pts
66Tulare County30.2-0.3 pts
67Grant County30.1-0.7 pts
68Scotland County30.1-0.2 pts
69Lyman County30+0.1 pts
70Caribou County29.90 pts
71Hanson County29.9-0.4 pts
72Hamilton County29.9+0.3 pts
73Davis County29.7+0.3 pts
74Finney County29.6-0.3 pts
75Maverick County29.6-0.4 pts
76Cache County29.5-0.3 pts
77Mahnomen County29.4-0.4 pts
78Pottawatomie County29.30 pts
79Texas County29.2+0.2 pts
80Geary County29.2-0.2 pts
81Emery County29.1-0.4 pts
82Blaine County29.1-0.3 pts
83Dallam County29.1-0.5 pts
84Daviess County29.1-0 pts
85Lea County29.1-0.1 pts
86McKenzie County29+0.2 pts
87Merced County29-0.3 pts
88Yoakum County29-0.1 pts
89Rockland County29+0.3 pts
90Oldham County29-0.8 pts
91Parmer County28.9-0.5 pts
92Kendall County28.9-0.2 pts
93Clark County28.9-0 pts
93San Juan County28.9-0.7 pts
95Martin County28.9+0.1 pts
96Cameron County28.9-0.6 pts
97Hemphill County28.9-0.2 pts
98Oneida County28.9-0.3 pts
99Dakota County28.8+0.2 pts
100Stevens County28.8-0.5 pts
101Minidoka County28.8+0.2 pts
102Charles Mix County28.8-0.2 pts
103Lyon County28.8-0.3 pts
104Uinta County28.8-0.3 pts
105Iron County28.8-0.5 pts
106Bryan County28.70 pts
107Grant County28.6-0.3 pts
108Hansford County28.6-0.2 pts
109Castro County28.6+0.1 pts
110Kaufman County28.5+0.3 pts
111Lake and Peninsula Borough28.5+0.4 pts
112Lincoln County28.5-0.2 pts
113Kearny County28.4+0.1 pts
114Yakima County28.4-0.3 pts
115Stanton County28.4-0 pts
116Canyon County28.4-0.5 pts
117Kern County28.4-0.2 pts
118Loudoun County28.4-0.3 pts
119Sherman County28.4-1.1 pts
120Reagan County28.3-0.1 pts
121Greenlee County28.3-0.3 pts
122Wright County28.3-0.1 pts
123Elko County28.3-0 pts
124Zavala County28.3-0.8 pts
125Sevier County28.20 pts
126Hoke County28.2-0.1 pts
127Tunica County28.2-0.6 pts
128Sanpete County28.2-0.1 pts
129Lincoln County28.2-1.5 pts
130Roberts County28.2+0.1 pts
131Lynn County28.2+0.4 pts
132Crane County28.2-0.8 pts
133Graham County28.1-0.2 pts
134Forsyth County28.1-0.4 pts
135Gray County28.1-0.5 pts
136Mountrail County28.1+0.5 pts
137Winkler County28-0.6 pts
138Campbell County28-0 pts
139Colusa County28-0.2 pts
140Weber County28-0.5 pts
141Dallas County28-0.3 pts
142McKinley County28-0.4 pts
143Chambers County27.9+0.1 pts
144Dawson County27.9-0 pts
145Sioux County27.90 pts
146Nobles County27.9+0.4 pts
147Fresno County27.8-0.2 pts
148Ector County27.8-0.1 pts
149Williamson County27.7-0.3 pts
150Sarpy County27.7-0.1 pts
151Titus County27.6-0.2 pts
152Fremont County27.6-0.9 pts
153Fort Bend County27.6-0.2 pts
154Cochran County27.6-0.6 pts
155Bear Lake County27.6+0.2 pts
156Twin Falls County27.5-0.2 pts
157Gooding County27.5-0.6 pts
158Madera County27.5-0.1 pts
159Oconee County27.5-0.2 pts
160Morrow County27.5-0.2 pts
161St. Bernard Parish27.5-0.1 pts
162Midland County27.4-0.1 pts
163Hamilton County27.4-0.3 pts
164Dimmit County27.4-0.3 pts
165Elkhart County27.4-0.2 pts
166Jim Hogg County27.4-0.6 pts
167Scott County27.3-0.4 pts
168Lamb County27.3-0.2 pts
169Carver County27.3-0.3 pts
170Ascension Parish27.2-0.2 pts
171Union County27.2-0.4 pts
172Owyhee County27.2-0.4 pts
173Wyandotte County27.2-0.2 pts
174Scott County27.2+0.1 pts
175Rockwall County27.2-0.2 pts
176Terry County27.2-0.4 pts
177Williams County27.1+0.7 pts
178Beadle County27.1+0.2 pts
179Hall County27.10 pts
180Matanuska-Susitna Borough27.1-0.2 pts
181Neshoba County27.1-0.3 pts
182Upton County27.1-0.9 pts
183Montgomery County27.1-0 pts
184Canadian County27-0 pts
185Kingfisher County26.9-0.4 pts
186Prince William County26.9-0.3 pts
187Effingham County26.9-0 pts
188Manassas Park city26.9-0.4 pts
189Yuba County26.9-0.3 pts
190Sterling County26.9+0.5 pts
191Benton County26.9-0.2 pts
192Delaware County26.8-0.4 pts
193Rosebud County26.8-0.5 pts
194Crawford County26.8+0.2 pts
195Webster County26.8-0.3 pts
196Ellis County26.8-0.1 pts
197Floyd County26.8-0.8 pts
197Ward County26.8-0.1 pts
199Atascosa County26.8-0.2 pts
200Todd County26.8-0.2 pts
201Val Verde County26.8-0.2 pts
202Clark County26.8+0.5 pts
203Curry County26.7-0.1 pts
204Oldham County26.7-0.1 pts
205Washington County26.7-0.4 pts
206Jeff Davis County26.7-0.2 pts
207Bell County26.7-0.3 pts
208San Juan County26.7-0.4 pts
209Harnett County26.7-0.2 pts
210Payette County26.6-0.3 pts
211Paulding County26.6-0.2 pts
212Jim Wells County26.6-0.5 pts
213Stafford County26.6-0.1 pts
214Fallon County26.6-0.3 pts
215Kings County26.6-0.2 pts
216Imperial County26.6-0.4 pts
217San Joaquin County26.6-0.3 pts
218Salt Lake County26.6-0.5 pts
219Weld County26.6-0.2 pts
220Moody County26.5+0.6 pts
221Yuma County26.50 pts
222Sweetwater County26.5-0.4 pts
223Boone County26.5-0.2 pts
224Morgan County26.5-0.1 pts
225Boone County26.5-0.2 pts
226Sherburne County26.5-0.3 pts
227Benton County26.5-0.2 pts
228Liberty County26.5-0.5 pts
229Logan County26.4-0.3 pts
230Buchanan County26.4-0.1 pts
231Crittenden County26.4-0.2 pts
232Conejos County26.4-0.7 pts
233Scott County26.4-0.6 pts
234Stanislaus County26.4-0.2 pts
235Adair County26.4+0.1 pts
236Saline County26.4+0.5 pts
237Chaves County26.4-0.3 pts
238Columbia County26.3-0.1 pts
239Clayton County26.3-0.4 pts
240Arthur County26.3-1.2 pts
241Crosby County26.3-0.3 pts
242Lincoln County26.3-0.1 pts
243Dodge County26.3-0.1 pts
244Collin County26.3-0.3 pts
245Schley County26.3-0.9 pts
246Eddy County26.3+0.2 pts
247Hill County26.30 pts
248Dewey County26.3+0.2 pts
249Montgomery County26.3-0.2 pts
250Bannock County26.3-0.2 pts

Showing the top 250 of 3135. The Excel download has every row.

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. 9 counties with data in other periods have no value for 2019 and are left out rather than filled from another source. 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 (US counties by population under 18, 2019) [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, US counties by population under 18, 2019. 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/us-counties?period=2019. 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. US counties by population under 18, 2019. 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/us-counties?period=2019.

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, US counties by population under 18, 2019 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/us-counties?period=2019 (Accessed: 12 October 2026).

BibTeX
@misc{census_us_counties_by_population_2019,
  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: US counties by population under 18, 2019}},
  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/us-counties?period=2019. 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: US counties by population under 18, 2019
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/us-counties?period=2019
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/us-counties?period=2019.
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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Questions

Which county has the highest population under 18?

Kusilvak Census Area, with 40.7% in 2019, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Sumter County, with 7.1% in 2019.

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. 9 counties have no value for 2019 and are not ranked.

Population under 18: other rankings

US counties: more rankings