Data / Rankings / Population under 18 / US counties

US counties by population under 18, 2025

Kusilvak Census Area had the highest population under 18 of 3144 counties in 2025, at 41.4%. Aleutians East Borough had the lowest, at 6.6%. The median was 21.4% and the figure for the United States was 21.1%. Source: the U.S. Census Bureau.

Highest41.4Kusilvak Census Area
Lowest6.6Aleutians East Borough
Median21.43144 counties
United States21.1History

Top 40 counties, 2025

Kusilvak Census Area: 41.4 %Kusilvak Census Area41.4Mellette County: 40.9 %Mellette County40.9Dewey County: 38.7 %Dewey County38.7Northwest Arctic Borough: 36.7 %Northwest Arctic Borough36.7Todd County: 36.6 %Todd County36.6Gaines County: 36 %Gaines County36Thurston County: 35.6 %Thurston County35.6Corson County: 35.6 %Corson County35.6Bethel Census Area: 35.2 %Bethel Census Area35.2Oglala Lakota County: 35.1 %Oglala Lakota County35.1Buffalo County: 35 %Buffalo County35Jackson County: 35 %Jackson County35Sioux County: 32.9 %Sioux County32.9Dallam County: 32.9 %Dallam County32.9Benson County: 32.9 %Benson County32.9Adams County: 32.7 %Adams County32.7Ziebach County: 32.7 %Ziebach County32.7Juab County: 32.6 %Juab County32.6Hamlin County: 32.5 %Hamlin County32.5Rolette County: 32.1 %Rolette County32.1Nome Census Area: 31.9 %Nome Census Area31.9Yoakum County: 31.9 %Yoakum County31.9LaGrange County: 31.5 %LaGrange County31.5Roosevelt County: 31.3 %Roosevelt County31.3Rockland County: 31.1 %Rockland County31.1Bailey County: 31 %Bailey County31Menominee County: 31 %Menominee County31Geary County: 30.9 %Geary County30.9Bennett County: 30.9 %Bennett County30.9Loving County: 30.8 %Loving County30.8Adams County: 30.7 %Adams County30.7Scotland County: 30.6 %Scotland County30.6Andrews County: 30.4 %Andrews County30.4Jefferson County: 30.3 %Jefferson County30.3Long County: 30.3 %Long County30.3McKenzie County: 30.3 %McKenzie County30.3Moore County: 30.3 %Moore County30.3Holmes County: 30.2 %Holmes County30.2Big Horn County: 30.2 %Big Horn County30.2Morgan County: 30.1 %Morgan County30.1
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2025 (%)Change on 2024
1Kusilvak Census Area41.4-0.1 pts
2Mellette County40.9+2.9 pts
3Dewey County38.7-0.1 pts
4Northwest Arctic Borough36.7+1 pts
5Todd County36.6-1.2 pts
6Gaines County36+0.4 pts
7Thurston County35.60 pts
8Corson County35.60 pts
9Bethel Census Area35.2-0.2 pts
10Oglala Lakota County35.1-0.5 pts
11Buffalo County35-1.4 pts
12Jackson County35-0.6 pts
13Sioux County32.9-1 pts
14Dallam County32.9-0.3 pts
15Benson County32.9-0.1 pts
16Adams County32.7-0.2 pts
17Ziebach County32.7+0.5 pts
18Juab County32.6-0.4 pts
19Hamlin County32.5-0.3 pts
20Rolette County32.1-0.6 pts
21Nome Census Area31.9-0.5 pts
22Yoakum County31.9+0.2 pts
23LaGrange County31.5-0.4 pts
24Roosevelt County31.3-0.2 pts
25Rockland County31.1+0.2 pts
26Bailey County31+0.8 pts
27Menominee County31-0.8 pts
28Geary County30.9+0.1 pts
29Bennett County30.9+0.1 pts
30Loving County30.8-5.4 pts
31Adams County30.7-0.5 pts
32Scotland County30.6+0.2 pts
33Andrews County30.4-0.3 pts
34Jefferson County30.3-0.9 pts
35Long County30.3-0.2 pts
36McKenzie County30.30 pts
37Moore County30.3-0.1 pts
38Holmes County30.2-0 pts
39Big Horn County30.2-0.6 pts
40Morgan County30.1-1.3 pts
41Davis County30+0.3 pts
42Tooele County29.9-0.7 pts
43Duchesne County29.9-0.6 pts
44Seward County29.9-0 pts
45Deaf Smith County29.8-0.1 pts
46Utah County29.8-0.6 pts
47Ford County29.8-0.3 pts
48Maverick County29.8-0.1 pts
49Liberty County29.6+0.1 pts
50Dillingham Census Area29.6-0.6 pts
51Daviess County29.5-0.1 pts
52Starr County29.5-0.3 pts
53Cassia County29.5-0.5 pts
54Franklin County29.4-0.4 pts
55Martin County29.3-0.2 pts
56Colfax County29.3-0.8 pts
57Clark County29.2-0 pts
58Dakota County29.2+0.5 pts
59Mahnomen County29.2-0.2 pts
60Uintah County29.2-0.9 pts
61Lynn County29.10 pts
62Jerome County29.1-0.2 pts
63Kaufman County29-0.1 pts
64Zavala County29-0.3 pts
65Crane County29-0.2 pts
66Ector County29-0.1 pts
67Midland County28.9-0.1 pts
68Webb County28.9-0.4 pts
69Franklin County28.9-0.6 pts
70Zapata County28.8-0.6 pts
71Haskell County28.7+0.6 pts
72Mountrail County28.7+0.2 pts
73Box Elder County28.6-0.6 pts
74Nobles County28.6-0.3 pts
75Hidalgo County28.5-0.4 pts
76Beadle County28.5+0.3 pts
77Grant County28.5-0.3 pts
78Hamilton County28.4-0.7 pts
79Millard County28.4-0.5 pts
80Gray County28.4-0.4 pts
81Terry County28.40 pts
82Williams County28.4+0.1 pts
83Cochran County28.3+0.3 pts
84Kearny County28.3-0.3 pts
85Schuyler County28.2+0.4 pts
86Glacier County28.2-0.5 pts
87Roberts County28.2-0.1 pts
88Charles Mix County28.2-0.2 pts
89Davis County28.2-0.8 pts
90Clark County28.1-0.2 pts
91Tulare County28.1-0.5 pts
92Beaver County28.1-0.4 pts
93Ward County28.1+0.1 pts
94Pottawatomie County28.1-0.3 pts
95Finney County28-0.6 pts
96Bonneville County28-0.5 pts
97Texas County28+0.2 pts
98Oneida County28+0.2 pts
99Castro County28-0.2 pts
100Hanson County27.9-0.5 pts
101Caribou County27.9-0.4 pts
102Sherman County27.8-0.3 pts
103Parmer County27.8-0.2 pts
104Lea County27.8-0.5 pts
105Dawson County27.7-0.2 pts
106Lyman County27.7+0.5 pts
107Bingham County27.6-0.5 pts
108Watonwan County27.6-0.1 pts
109Christian County27.6-0.3 pts
110Scott County27.6-0.1 pts
111Lake and Peninsula Borough27.6-0.5 pts
112Rosebud County27.5-0.2 pts
113Wichita County27.5-0.1 pts
114Adair County27.4+0.1 pts
115Turner County27.4+0.3 pts
116Ochiltree County27.3-0.3 pts
117Webster County27.3-0.3 pts
118Liberty County27.3+0.3 pts
119Winkler County27.3-0.2 pts
120Todd County27.2+0.2 pts
121Power County27.2-0.5 pts
122Sevier County27.2-0.6 pts
123Hansford County27.2-0.2 pts
124Reagan County27.2-0.6 pts
125Cache County27.2-0.2 pts
126Bryan County27.2-0.3 pts
127Yuma County27.2-0.2 pts
128Minidoka County27.1-0.2 pts
129Kern County27.1-0.5 pts
130Dimmit County27-0.5 pts
131Wallace County27+0.2 pts
132Sevier County27-0.5 pts
133Rich County27-1.1 pts
134Hill County270 pts
135Gove County26.9+0.5 pts
136Emery County26.9-0.4 pts
137Chambers County26.9-0.4 pts
138Sterling County26.8-0.6 pts
139Lyon County26.8-0.8 pts
140Merced County26.8-0.5 pts
141Faulk County26.8+1.1 pts
142Yakima County26.7-0.5 pts
143McCook County26.7-0.2 pts
144San Juan County26.7-0.8 pts
145Grant County26.7-0.4 pts
146Hoke County26.7-0.2 pts
147Cameron County26.6-0.4 pts
148Uvalde County26.6+0.2 pts
149Blaine County26.6-0.3 pts
150Val Verde County26.6-0.3 pts
151Stevens County26.6-0.4 pts
152Franklin city26.5+0.1 pts
153Sioux County26.5-0.5 pts
154Moody County26.4-0.8 pts
155Wayne County26.40 pts
156Morgan County26.4+0.1 pts
157Greenlee County26.4-0.7 pts
158Robeson County26.40 pts
159Gentry County26.4+0.2 pts
160Wright County26.3-0.5 pts
161Stanton County26.30 pts
162Clark County26.3+0.7 pts
163Hockley County26.3-0.3 pts
164Neshoba County26.3-0.5 pts
165Fresno County26.3-0.4 pts
166Elko County26.3-0.5 pts
167Curry County26.2-0.3 pts
168Titus County26.2-0.2 pts
169Yuba County26.2-0.4 pts
170Reeves County26.2-0.2 pts
171Bell County26.2-0.3 pts
172Jim Wells County26.2-0.1 pts
173Madera County26.2-0.4 pts
173McCurtain County26.2-0 pts
175Pemiscot County26.2+0.1 pts
176Hall County26.2-0.2 pts
177Graham County26.2-0.3 pts
177Imperial County26.2-0.3 pts
179Lincoln County26.2-0.3 pts
180Dunn County26.1+0.2 pts
181Atascosa County26.1-0.3 pts
182Manassas city26-0.1 pts
183Meade County26-0.1 pts
184Wyandotte County26-0.3 pts
185Conejos County26-0.4 pts
185Elkhart County26-0.3 pts
187Ripley County26+0.5 pts
188Fairfax city26+1.3 pts
189Stark County26-0 pts
190Hayes County25.9-0.7 pts
191Frio County25.9+0.3 pts
192Campbell County25.9-0.6 pts
193Kingfisher County25.9-0.4 pts
194Grant County25.9-0.1 pts
195Wasatch County25.9-0.9 pts
196Colusa County25.9-0.6 pts
197Lamb County25.9-0.5 pts
198Rockwall County25.9-0.4 pts
199Jim Hogg County25.9-0.4 pts
200Camp County25.9-0.3 pts
201Hutchinson County25.8-0.1 pts
202Pipestone County25.8-0 pts
203Wright County25.8-0.2 pts
204Montgomery County25.8-0.4 pts
205Ellis County25.8-0.3 pts
206Canyon County25.8-0.5 pts
207Nemaha County25.8-0.1 pts
208George County25.8+0.1 pts
209Carroll County25.7-0.1 pts
210Douglas County25.7+0.1 pts
211Mercer County25.7+0.1 pts
212Grundy County25.7+0.1 pts
213Stafford County25.7-0.4 pts
214Logan County25.7+0.1 pts
215Tripp County25.7-0.1 pts
216Dunklin County25.7-0 pts
217Acadia Parish25.7-0.1 pts
218Hamilton County25.7+0.1 pts
219Saline County25.7-0.5 pts
220Kendall County25.7-0.7 pts
221Jay County25.6-0.2 pts
222Morrow County25.6-0.3 pts
223Fort Bend County25.6-0.6 pts
224Effingham County25.6-0.5 pts
225Marshall County25.6-0.9 pts
226Vernon County25.6-0.3 pts
227Marshall County25.6-0.1 pts
228Buchanan County25.5+0.1 pts
229Crittenden County25.5-0.4 pts
230Lafayette County25.5+0.1 pts
231Tunica County25.5-0.6 pts
232St. Bernard Parish25.5-0.6 pts
233Platte County25.5-0.2 pts
234Dallas County25.5-0.4 pts
235Blaine County25.5-0.4 pts
236Greeley County25.5-0.5 pts
237Prowers County25.4-0.1 pts
238Glasscock County25.4+0.4 pts
239McDonald County25.40 pts
240Ascension Parish25.4-0.5 pts
241Eddy County25.4+0.1 pts
242Kings County25.4-0.5 pts
243Crawford County25.4-0.7 pts
243Gonzales County25.4-0.2 pts
243Jerauld County25.4+0.1 pts
246St. Landry Parish25.4-0.2 pts
247Todd County25.4+0.1 pts
248Clay County25.3+0.4 pts
249Buena Vista County25.3-0.5 pts
250Navarro County25.3-0.3 pts

Showing the top 250 of 3144. 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. 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.

Use this data in your AI agent

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Rank US counties by population under 18 using official data, and cite the source.
rank_places {"indicator":"population_0_17_share","level":"province","within":"United States","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_0_17_share&level=province&within=United%20States&limit=10

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Questions

Which county has the highest population under 18?

Kusilvak Census Area, with 41.4% in 2025, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Aleutians East Borough, with 6.6% in 2025.

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

US counties: more rankings