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 2015, at 40.7%. Sumter County had the lowest, at 7.3%. The median was 22.4% and the figure for the United States was 22.9%. Source: the U.S. Census Bureau.

Highest40.7Kusilvak Census Area
Lowest7.3Sumter County
Median22.43135 counties
United States22.9History

Top 40 counties, 2015

Kusilvak Census Area: 40.7 %Kusilvak Census Area40.7Todd County: 40.7 %Todd County40.7Buffalo County: 39.6 %Buffalo County39.6Loving County: 38.7 %Loving County38.7Oglala Lakota County: 38.3 %Oglala Lakota County38.3Ziebach County: 37.7 %Ziebach County37.7Sioux County: 37.3 %Sioux County37.3Bethel Census Area: 36.1 %Bethel Census Area36.1Morgan County: 35.8 %Morgan County35.8Northwest Arctic Borough: 35.5 %Northwest Arctic Borough35.5Thurston County: 35.3 %Thurston County35.3Juab County: 35 %Juab County35Jefferson County: 35 %Jefferson County35Gaines County: 34.9 %Gaines County34.9Tooele County: 34.8 %Tooele County34.8Utah County: 34.8 %Utah County34.8Corson County: 34.8 %Corson County34.8Uintah County: 34.5 %Uintah County34.5Nome Census Area: 34.3 %Nome Census Area34.3Adams County: 34.3 %Adams County34.3Duchesne County: 34.2 %Duchesne County34.2Franklin County: 33.9 %Franklin County33.9Rolette County: 33.9 %Rolette County33.9LaGrange County: 33.8 %LaGrange County33.8Benson County: 33.6 %Benson County33.6Davis County: 33.6 %Davis County33.6Big Horn County: 33.3 %Big Horn County33.3Franklin County: 33.1 %Franklin County33.1Zapata County: 33.1 %Zapata County33.1Webb County: 33 %Webb County33Bennett County: 32.9 %Bennett County32.9Box Elder County: 32.9 %Box Elder County32.9Holmes County: 32.9 %Holmes County32.9Menominee County: 32.9 %Menominee County32.9Hidalgo County: 32.7 %Hidalgo County32.7Wasatch County: 32.5 %Wasatch County32.5Cassia County: 32.5 %Cassia County32.5Dewey County: 32.3 %Dewey County32.3Bailey County: 32.3 %Bailey County32.3Hanson County: 32.2 %Hanson County32.2
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2015 (%)Change on 2014
1Kusilvak Census Area40.7-0.5 pts
2Todd County40.7+0.4 pts
3Buffalo County39.6-0.6 pts
4Loving County38.7+8.5 pts
5Oglala Lakota County38.3+0.1 pts
6Ziebach County37.7-0.8 pts
7Sioux County37.3-0.2 pts
8Bethel Census Area36.10 pts
9Morgan County35.8-0.1 pts
10Northwest Arctic Borough35.5-0.4 pts
11Thurston County35.3+0.3 pts
12Juab County35-0.3 pts
13Jefferson County35-0.1 pts
14Gaines County34.9+0.2 pts
15Tooele County34.8-0.3 pts
16Utah County34.8-0.2 pts
17Corson County34.8+0.9 pts
18Uintah County34.5+0.3 pts
19Nome Census Area34.3-0 pts
20Adams County34.3-0.1 pts
21Duchesne County34.2+0.3 pts
22Franklin County33.9-0.4 pts
23Rolette County33.9-0.1 pts
24LaGrange County33.8-0.1 pts
25Benson County33.6+0.1 pts
26Davis County33.6-0.2 pts
27Big Horn County33.3-0.2 pts
28Franklin County33.1-0.2 pts
29Zapata County33.1+0.1 pts
30Webb County33-0.4 pts
31Bennett County32.9-0.5 pts
32Box Elder County32.9-0.3 pts
33Holmes County32.9-0.4 pts
34Menominee County32.9+0.2 pts
35Hidalgo County32.7-0.4 pts
36Wasatch County32.5-0.4 pts
37Cassia County32.5-0.1 pts
38Dewey County32.3-0.1 pts
39Bailey County32.3+1 pts
40Hanson County32.2-0.2 pts
41Starr County32-0.3 pts
42Grant County32-0.1 pts
43Jackson County31.9-0.9 pts
44Bingham County31.8-0.2 pts
45Millard County31.7+0.3 pts
46Lincoln County31.5-0.3 pts
47Hemphill County31.5+0.6 pts
48Hamlin County31.4-0.2 pts
49Ochiltree County31.4+0.1 pts
50San Juan County31.4-0.5 pts
51Deaf Smith County31.4-0.3 pts
52Seward County31.4-0 pts
53Bonneville County31.3-0.1 pts
54Maverick County31.3-0.2 pts
55Adams County31.30 pts
56Tulare County31.3-0.2 pts
57Roosevelt County31.3+0.2 pts
58Jerome County31.2+0.1 pts
59Glacier County31.1-0.1 pts
60Finney County31.1-0.1 pts
61Power County31+0.2 pts
62Oldham County31+0.1 pts
63Yoakum County31+0.1 pts
64Sevier County31-0.1 pts
65Cameron County31-0.4 pts
66Moore County30.9-0.1 pts
67Ford County30.9-0.1 pts
68Beaver County30.9-0.4 pts
69Dillingham Census Area30.9-0.4 pts
70Mellette County30.9-0.6 pts
71Stevens County30.8-0.2 pts
72Rich County30.7+0.5 pts
73Cache County30.7-0.3 pts
74Emery County30.6-0.9 pts
75Zavala County30.50 pts
76Andrews County30.4+0.3 pts
77Crane County30.2+0.2 pts
78Long County30.2-0.1 pts
79Canyon County30.2-0.2 pts
80Hamilton County30.2-0.3 pts
81Kendall County30-0.3 pts
82Uinta County30-0 pts
83Lea County300 pts
84Haskell County29.9+0.4 pts
85Geary County29.9-0.3 pts
86Dallam County29.9-0.2 pts
87Colfax County29.80 pts
88Grant County29.8-0.1 pts
89Merced County29.8-0.2 pts
90Winkler County29.8+0.3 pts
91Blaine County29.7+0.1 pts
92Mahnomen County29.7-0.2 pts
93Martin County29.70 pts
94McKinley County29.6-0.1 pts
95Parmer County29.6+0.1 pts
96Forsyth County29.6-0.2 pts
97Tunica County29.5-0.3 pts
98Cochran County29.5+0.3 pts
99Lincoln County29.5-0.1 pts
100Charles Mix County29.5+0.4 pts
101Loudoun County29.4-0.2 pts
102Fremont County29.4-0.3 pts
103Iron County29.4+0.1 pts
104Yakima County29.4-0.2 pts
105Dimmit County29.4-0.5 pts
106Hansford County29.4+0.5 pts
107Gray County29.30 pts
108Jim Hogg County29.3-0.2 pts
109Caribou County29.2-0.2 pts
110Castro County29.2-0.5 pts
111Stanton County29.2+0.8 pts
112Lyman County29.2-0.2 pts
113Kern County29.2-0.2 pts
114Weber County29.2-0.3 pts
115Dakota County29.1-0.1 pts
116Pottawatomie County29-0.3 pts
117Hoke County29-0.2 pts
118Clark County28.9-0.1 pts
119Wright County28.9-0.3 pts
120Minidoka County28.9-0.1 pts
121Greenlee County28.9+0.1 pts
122Dallas County28.9-0.2 pts
123Bryan County28.8+0.1 pts
124Scotland County28.8-0.1 pts
125Sanpete County28.8-0.3 pts
126Daviess County28.8-0.1 pts
127Texas County28.8+0.2 pts
128Hamilton County28.8-0.3 pts
129Scott County28.8-0.2 pts
130Sevier County28.8-0.4 pts
131Reagan County28.7-1.1 pts
132Campbell County28.7+0.1 pts
133Oneida County28.7+0.8 pts
134Kearny County28.7-0.2 pts
135Union County28.6-0.4 pts
136Lyon County28.6+0.1 pts
137Washington County28.6-0.5 pts
138Ector County28.60 pts
139Sherman County28.6+0.3 pts
140Schleicher County28.6-0.9 pts
141Graham County28.6-0.3 pts
142Davis County28.5-0.2 pts
143Teton County28.5-0.1 pts
144Fresno County28.5-0.2 pts
145Williamson County28.5-0 pts
146Titus County28.5-0.3 pts
147Douglas County28.5-0.4 pts
148Gooding County28.5-0.3 pts
149Manassas Park city28.4-0.4 pts
150Rosebud County28.4-0.2 pts
151Sarpy County28.3-0.1 pts
152McKenzie County28.3+0.5 pts
153Dawson County28.2-0 pts
154Elko County28.2-0 pts
155Fort Bend County28.2-0.2 pts
156Colusa County28.2-0.2 pts
157Kaufman County28.1+0.1 pts
158Kenedy County28.1-0.9 pts
159Salt Lake County28.1-0.2 pts
160Jim Wells County28.1+0.1 pts
161Schley County28.1-0.2 pts
162Conejos County28.1-0.4 pts
163Elkhart County28+0.1 pts
164Carver County28-0.3 pts
165Twin Falls County28+0.2 pts
166Val Verde County28-0.3 pts
167Rockwall County28-0.2 pts
168Morrow County28-0.2 pts
169Neshoba County280 pts
169Rockland County28+0.1 pts
171Lamb County28-0.2 pts
172Lake and Peninsula Borough27.9-0.2 pts
173Paulding County27.9-0.4 pts
174Delaware County27.9-0.2 pts
175Apache County27.9-0.6 pts
176San Juan County27.8-0.2 pts
177Arthur County27.8-1.8 pts
178Wyandotte County27.8-0.2 pts
179Madera County27.8-0.1 pts
180Prince William County27.8-0.2 pts
181Chambers County27.8-0 pts
182Roberts County27.8-0.2 pts
182Santa Cruz County27.8-0.4 pts
184Ascension Parish27.8-0.1 pts
185St. Bernard Parish27.8+0.3 pts
186Crosby County27.8+0.6 pts
187Imperial County27.8-0.3 pts
188Jeff Davis County27.7+0.1 pts
189Upton County27.7-0.1 pts
190Owyhee County27.70 pts
191Matanuska-Susitna Borough27.70 pts
192Bear Lake County27.7-0.2 pts
193Adams County27.7-0.2 pts
194Sioux County27.6+0.1 pts
195Navajo County27.6-0.4 pts
196Clark County27.6-2.1 pts
197Benton County27.6-0.1 pts
198El Paso County27.6-0.4 pts
199Harnett County27.6-0.2 pts
200Oconee County27.5-0 pts
201San Joaquin County27.5-0.3 pts
202Clayton County27.5-0.2 pts
203Atascosa County27.5-0.2 pts
204Liberty County27.5-0.8 pts
205Gwinnett County27.4-0.3 pts
205Sweetwater County27.4-0 pts
207Boone County27.4-0 pts
208Kingfisher County27.4+0.2 pts
209Collin County27.4-0.2 pts
210Lincoln County27.4+0.1 pts
211Payette County27.40 pts
212Yuba County27.4-0.1 pts
213Echols County27.4+0.1 pts
214Montgomery County27.3-0 pts
215Atkinson County27.3-0.6 pts
216Sherburne County27.3-0.2 pts
217Bell County27.3-0.1 pts
218Todd County27.3-0 pts
219Crittenden County27.3-0.2 pts
220Dodge County27.3-0.6 pts
221Ellis County27.3-0.1 pts
222Boone County27.3-0 pts
223Chaves County27.2-0.2 pts
224Floyd County27.20 pts
225Kings County27.2-0.2 pts
226Weld County27.2-0.1 pts
227Midland County27.2+0.1 pts
228Williamson County27.2-0.4 pts
229Curry County27.2-0.1 pts
230Terry County27.2+0.2 pts
231Effingham County27.2-0.2 pts
232Hale County27.2-0.3 pts
233Webster County27.1-0 pts
234Hall County27.1+0.3 pts
235Whitfield County27.1-0.2 pts
236Canadian County27.1+0.1 pts
237Coahoma County27.1-0.3 pts
238Ward County27.10 pts
239Bannock County27.1-0 pts
240Grant County27.1-0.3 pts
241Christian County27-0.3 pts
242Stafford County27-0.3 pts
243Humboldt County27+0.1 pts
244Morgan County27-0 pts
245Piute County27+0.2 pts
246Wichita County27+0.5 pts
247Fallon County26.9+1.1 pts
248Stanislaus County26.9-0.2 pts
249King County26.9+3.4 pts
250Buchanan County26.9-0 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 2015 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, 2015) [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, 2015. 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=2015. 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, 2015. 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=2015.

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, 2015 [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=2015 (Accessed: 12 October 2026).

BibTeX
@misc{census_us_counties_by_population_2015,
  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, 2015}},
  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=2015. 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, 2015
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=2015
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/us-counties?period=2015.
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 2015, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Sumter County, with 7.3% in 2015.

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 2015 and are not ranked.

Population under 18: other rankings

US counties: more rankings