Counties in California by population under 18

Tulare County had the highest population under 18 of 58 counties in 2015, at 31.3%. San Francisco County had the lowest, at 13.2%. The median was 21.7% and the figure for California was 23.3%. Source: the U.S. Census Bureau.

Highest31.3Tulare County
Median21.758 counties
California23.3History

All counties, 2015

Tulare County: 31.3 %Tulare County31.3Merced County: 29.8 %Merced County29.8Kern County: 29.2 %Kern County29.2Fresno County: 28.5 %Fresno County28.5Colusa County: 28.2 %Colusa County28.2Madera County: 27.8 %Madera County27.8Imperial County: 27.8 %Imperial County27.8San Joaquin County: 27.5 %San Joaquin County27.5Yuba County: 27.4 %Yuba County27.4Kings County: 27.2 %Kings County27.2Stanislaus County: 26.9 %Stanislaus County26.9San Bernardino County: 26.7 %San Bernardino County26.7San Benito County: 26.4 %San Benito County26.4Glenn County: 26.4 %Glenn County26.4Monterey County: 26.3 %Monterey County26.3Riverside County: 26.1 %Riverside County26.1Sutter County: 26 %Sutter County26Sacramento County: 24.2 %Sacramento County24.2Tehama County: 24.1 %Tehama County24.1Ventura County: 23.8 %Ventura County23.8Contra Costa County: 23.5 %Contra Costa County23.5Placer County: 23.1 %Placer County23.1Solano County: 22.7 %Solano County22.7Santa Clara County: 22.6 %Santa Clara County22.6Orange County: 22.5 %Orange County22.5Santa Barbara County: 22.3 %Santa Barbara County22.3Los Angeles County: 22.3 %Los Angeles County22.3San Diego County: 22 %San Diego County22Yolo County: 21.7 %Yolo County21.7Napa County: 21.6 %Napa County21.6San Mateo County: 21.4 %San Mateo County21.4Shasta County: 21.4 %Shasta County21.4Mendocino County: 21.4 %Mendocino County21.4Alameda County: 21.4 %Alameda County21.4El Dorado County: 21 %El Dorado County21Marin County: 20.8 %Marin County20.8Del Norte County: 20.8 %Del Norte County20.8Sonoma County: 20.6 %Sonoma County20.6Butte County: 20.3 %Butte County20.3Inyo County: 20.3 %Inyo County20.3Lake County: 20.1 %Lake County20.1Modoc County: 20.1 %Modoc County20.1Mono County: 20 %Mono County20Santa Cruz County: 19.9 %Santa Cruz County19.9Humboldt County: 19.8 %Humboldt County19.8Siskiyou County: 19.8 %Siskiyou County19.8San Luis Obispo County: 18.4 %San Luis Obispo County18.4Nevada County: 17.9 %Nevada County17.9Calaveras County: 17.6 %Calaveras County17.6Alpine County: 17.6 %Alpine County17.6Mariposa County: 16.7 %Mariposa County16.7Tuolumne County: 16.6 %Tuolumne County16.6Plumas County: 16.6 %Plumas County16.6Lassen County: 16.5 %Lassen County16.5Trinity County: 16.5 %Trinity County16.5Sierra County: 16.2 %Sierra County16.2Amador County: 15.8 %Amador County15.8San Francisco County: 13.2 %San Francisco County13.2
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2015 (%)Change on 2014
1Tulare County31.3-0.2 pts
2Merced County29.8-0.2 pts
3Kern County29.2-0.2 pts
4Fresno County28.5-0.2 pts
5Colusa County28.2-0.2 pts
6Madera County27.8-0.1 pts
7Imperial County27.8-0.3 pts
8San Joaquin County27.5-0.3 pts
9Yuba County27.4-0.1 pts
10Kings County27.2-0.2 pts
11Stanislaus County26.9-0.2 pts
12San Bernardino County26.7-0.4 pts
13San Benito County26.4-0.5 pts
14Glenn County26.4-0.3 pts
15Monterey County26.3-0.1 pts
16Riverside County26.1-0.3 pts
17Sutter County26-0.2 pts
18Sacramento County24.2-0.2 pts
19Tehama County24.10 pts
20Ventura County23.8-0.4 pts
21Contra Costa County23.5-0.2 pts
22Placer County23.1-0.2 pts
23Solano County22.7-0.2 pts
24Santa Clara County22.6-0.3 pts
25Orange County22.5-0.3 pts
26Santa Barbara County22.3-0.1 pts
27Los Angeles County22.3-0.4 pts
28San Diego County22-0.2 pts
29Yolo County21.7-0.2 pts
30Napa County21.6-0.3 pts
31San Mateo County21.4-0.2 pts
32Shasta County21.4-0.2 pts
33Mendocino County21.4-0.2 pts
34Alameda County21.4-0.2 pts
35El Dorado County21-0.2 pts
36Marin County20.80 pts
37Del Norte County20.8-0.5 pts
38Sonoma County20.6-0.2 pts
39Butte County20.3-0.1 pts
40Inyo County20.3-0.2 pts
41Lake County20.1-0 pts
42Modoc County20.1+0.1 pts
43Mono County20-0.4 pts
44Santa Cruz County19.9-0.2 pts
45Humboldt County19.8-0 pts
46Siskiyou County19.8-0.1 pts
47San Luis Obispo County18.4-0 pts
48Nevada County17.9-0.2 pts
49Calaveras County17.6-0.3 pts
50Alpine County17.6+0.2 pts
51Mariposa County16.7-0 pts
52Tuolumne County16.6-0.2 pts
53Plumas County16.6-0.3 pts
54Lassen County16.5-0.2 pts
55Trinity County16.50 pts
56Sierra County16.2+0.4 pts
57Amador County15.8+0.2 pts
58San Francisco County13.2-0 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 California 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, Counties in California 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/california-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. Counties in California 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/california-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, Counties in California 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/california-counties?period=2015 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_by_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: Counties in California 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/california-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: Counties in California 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/california-counties?period=2015
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/california-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  - 
Embed this chart

Paste this code into a web page or a blog post. The chart shows the latest figures as they are published, with the source and a link back to this page.

Sites that read oEmbed links, such as WordPress, can show the chart when you paste the link to this page.

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

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest population under 18?

Tulare County, with 31.3% in 2015, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

San Francisco County, with 13.2% 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.

Population under 18: other rankings

Counties in California: more rankings