Counties in California by population aged 18 to 64

San Francisco County had the highest population aged 18 to 64 of 58 counties in 2016, at 71.9%. Sierra County had the lowest, at 54.5%. The median was 60.3% and the figure for California was 63.4%. Source: the U.S. Census Bureau.

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Lowest54.5Sierra County
Median60.358 counties
California63.4History

Map of counties, 2016

Alameda County: 66 %Alpine County: 59.6 %Amador County: 57.2 %Butte County: 61.5 %Calaveras County: 56.3 %Colusa County: 57.9 %Contra Costa County: 61.8 %Del Norte County: 62 %El Dorado County: 59.7 %Fresno County: 59.6 %Glenn County: 58 %Humboldt County: 63.3 %Imperial County: 60.1 %Inyo County: 57.4 %Kern County: 60.5 %Kings County: 63.3 %Lake County: 58.2 %Lassen County: 70.4 %Los Angeles County: 65.2 %Madera County: 58.7 %Marin County: 58.8 %Mariposa County: 57.1 %Mendocino County: 58.3 %Merced County: 59.2 %Modoc County: 54.9 %Mono County: 66 %Monterey County: 61.3 %Napa County: 60.3 %Nevada County: 57.1 %Orange County: 63.9 %Placer County: 58.2 %Plumas County: 56.3 %Riverside County: 60.3 %Sacramento County: 62.5 %San Benito County: 61.4 %San Bernardino County: 62.3 %San Diego County: 64.7 %San Francisco County: 71.9 %San Joaquin County: 60.2 %San Luis Obispo County: 62.7 %San Mateo County: 63.8 %Santa Barbara County: 62.8 %Santa Clara County: 65.1 %Santa Cruz County: 65.1 %Shasta County: 57.9 %Sierra County: 54.5 %Siskiyou County: 56.2 %Solano County: 63 %Sonoma County: 61.6 %Stanislaus County: 60.2 %Sutter County: 59 %Tehama County: 56.8 %Trinity County: 59.8 %Tulare County: 57.7 %Tuolumne County: 58.6 %Ventura County: 61.7 %Yolo County: 66 %Yuba County: 60.6 %
  • Under 58
  • 58 to 59
  • 59 to 60
  • 60 to 62
  • 62 to 64
  • 64 and over
%, 2016. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2016

San Francisco County: 71.9 %San Francisco County71.9Lassen County: 70.4 %Lassen County70.4Yolo County: 66 %Yolo County66Alameda County: 66 %Alameda County66Mono County: 66 %Mono County66Los Angeles County: 65.2 %Los Angeles County65.2Santa Cruz County: 65.1 %Santa Cruz County65.1Santa Clara County: 65.1 %Santa Clara County65.1San Diego County: 64.7 %San Diego County64.7Orange County: 63.9 %Orange County63.9San Mateo County: 63.8 %San Mateo County63.8Humboldt County: 63.3 %Humboldt County63.3Kings County: 63.3 %Kings County63.3Solano County: 63 %Solano County63Santa Barbara County: 62.8 %Santa Barbara County62.8San Luis Obispo County: 62.7 %San Luis Obispo County62.7Sacramento County: 62.5 %Sacramento County62.5San Bernardino County: 62.3 %San Bernardino County62.3Del Norte County: 62 %Del Norte County62Contra Costa County: 61.8 %Contra Costa County61.8Ventura County: 61.7 %Ventura County61.7Sonoma County: 61.6 %Sonoma County61.6Butte County: 61.5 %Butte County61.5San Benito County: 61.4 %San Benito County61.4Monterey County: 61.3 %Monterey County61.3Yuba County: 60.6 %Yuba County60.6Kern County: 60.5 %Kern County60.5Riverside County: 60.3 %Riverside County60.3Napa County: 60.3 %Napa County60.3Stanislaus County: 60.2 %Stanislaus County60.2San Joaquin County: 60.2 %San Joaquin County60.2Imperial County: 60.1 %Imperial County60.1Trinity County: 59.8 %Trinity County59.8El Dorado County: 59.7 %El Dorado County59.7Fresno County: 59.6 %Fresno County59.6Alpine County: 59.6 %Alpine County59.6Merced County: 59.2 %Merced County59.2Sutter County: 59 %Sutter County59Marin County: 58.8 %Marin County58.8Madera County: 58.7 %Madera County58.7Tuolumne County: 58.6 %Tuolumne County58.6Mendocino County: 58.3 %Mendocino County58.3Placer County: 58.2 %Placer County58.2Lake County: 58.2 %Lake County58.2Glenn County: 58 %Glenn County58Colusa County: 57.9 %Colusa County57.9Shasta County: 57.9 %Shasta County57.9Tulare County: 57.7 %Tulare County57.7Inyo County: 57.4 %Inyo County57.4Amador County: 57.2 %Amador County57.2Nevada County: 57.1 %Nevada County57.1Mariposa County: 57.1 %Mariposa County57.1Tehama County: 56.8 %Tehama County56.8Calaveras County: 56.3 %Calaveras County56.3Plumas County: 56.3 %Plumas County56.3Siskiyou County: 56.2 %Siskiyou County56.2Modoc County: 54.9 %Modoc County54.9Sierra County: 54.5 %Sierra County54.5San Francisco County: 71.9 %San Francisco County71.9Lassen County: 70.4 %Lassen County70.4Yolo County: 66 %Yolo County66Alameda County: 66 %Alameda County66Mono County: 66 %Mono County66Los Angeles County: 65.2 %Los Angeles County65.2Santa Cruz County: 65.1 %Santa Cruz County65.1Santa Clara County: 65.1 %Santa Clara County65.1San Diego County: 64.7 %San Diego County64.7Orange County: 63.9 %Orange County63.9San Mateo County: 63.8 %San Mateo County63.8Humboldt County: 63.3 %Humboldt County63.3Kings County: 63.3 %Kings County63.3Solano County: 63 %Solano County63Santa Barbara County: 62.8 %Santa Barbara County62.8San Luis Obispo County: 62.7 %San Luis Obispo County62.7Sacramento County: 62.5 %Sacramento County62.5San Bernardino County: 62.3 %San Bernardino County62.3Del Norte County: 62 %Del Norte County62Contra Costa County: 61.8 %Contra Costa County61.8Ventura County: 61.7 %Ventura County61.7Sonoma County: 61.6 %Sonoma County61.6Butte County: 61.5 %Butte County61.5San Benito County: 61.4 %San Benito County61.4Monterey County: 61.3 %Monterey County61.3Yuba County: 60.6 %Yuba County60.6Kern County: 60.5 %Kern County60.5Riverside County: 60.3 %Riverside County60.3Napa County: 60.3 %Napa County60.3Stanislaus County: 60.2 %Stanislaus County60.2San Joaquin County: 60.2 %San Joaquin County60.2Imperial County: 60.1 %Imperial County60.1Trinity County: 59.8 %Trinity County59.8El Dorado County: 59.7 %El Dorado County59.7Fresno County: 59.6 %Fresno County59.6Alpine County: 59.6 %Alpine County59.6Merced County: 59.2 %Merced County59.2Sutter County: 59 %Sutter County59Marin County: 58.8 %Marin County58.8Madera County: 58.7 %Madera County58.7Tuolumne County: 58.6 %Tuolumne County58.6Mendocino County: 58.3 %Mendocino County58.3Placer County: 58.2 %Placer County58.2Lake County: 58.2 %Lake County58.2Glenn County: 58 %Glenn County58Colusa County: 57.9 %Colusa County57.9Shasta County: 57.9 %Shasta County57.9Tulare County: 57.7 %Tulare County57.7Inyo County: 57.4 %Inyo County57.4Amador County: 57.2 %Amador County57.2Nevada County: 57.1 %Nevada County57.1Mariposa County: 57.1 %Mariposa County57.1Tehama County: 56.8 %Tehama County56.8Calaveras County: 56.3 %Calaveras County56.3Plumas County: 56.3 %Plumas County56.3Siskiyou County: 56.2 %Siskiyou County56.2Modoc County: 54.9 %Modoc County54.9Sierra County: 54.5 %Sierra County54.5
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2016 (%)Change on 2015
1San Francisco County71.9-0.2 pts
2Lassen County70.4-0.5 pts
3Yolo County66-0.2 pts
4Alameda County66-0.1 pts
5Mono County66-0.6 pts
6Los Angeles County65.20 pts
7Santa Cruz County65.1-0.5 pts
8Santa Clara County65.1+0.1 pts
9San Diego County64.7-0.1 pts
10Orange County63.9-0.1 pts
11San Mateo County63.8-0.1 pts
12Humboldt County63.3-0.6 pts
13Kings County63.3-0 pts
14Solano County63-0.2 pts
15Santa Barbara County62.8-0.3 pts
16San Luis Obispo County62.7-0.6 pts
17Sacramento County62.5-0.2 pts
18San Bernardino County62.3-0.1 pts
19Del Norte County62-0.6 pts
20Contra Costa County61.8-0.2 pts
21Ventura County61.7-0.2 pts
22Sonoma County61.6-0.5 pts
23Butte County61.5-0.4 pts
24San Benito County61.4+0.1 pts
25Monterey County61.3-0.2 pts
26Yuba County60.60 pts
27Kern County60.5-0.1 pts
28Riverside County60.3-0 pts
29Napa County60.3-0.3 pts
30Stanislaus County60.2-0.2 pts
31San Joaquin County60.2-0.1 pts
32Imperial County60.1-0.1 pts
33Trinity County59.8-0.3 pts
34El Dorado County59.7-0.6 pts
35Fresno County59.6-0.2 pts
36Alpine County59.6-1 pts
37Merced County59.2-0.2 pts
38Sutter County59-0.2 pts
39Marin County58.8-0.5 pts
40Madera County58.7-0.4 pts
41Tuolumne County58.6-0.4 pts
42Mendocino County58.3-0.4 pts
43Placer County58.2-0.3 pts
44Lake County58.2-0.5 pts
45Glenn County58-0 pts
46Colusa County57.9-0.1 pts
46Shasta County57.9-0.6 pts
48Tulare County57.7-0.1 pts
49Inyo County57.4-0.5 pts
50Amador County57.2-0.8 pts
51Nevada County57.1-0.7 pts
52Mariposa County57.1-0.6 pts
53Tehama County56.8-0.5 pts
54Calaveras County56.3-0.2 pts
55Plumas County56.3-0.6 pts
56Siskiyou County56.2-0.6 pts
57Modoc County54.9-0.6 pts
58Sierra County54.5-1 pts

Other periods

About this ranking

Residents aged 18 to 64 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.

Not comparable with working-age shares for ages 15 to 64 used in EU and World Bank statistics.

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 18 to 64 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 18 to 64 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 aged 18 to 64, 2016) [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 18 to 64 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 aged 18 to 64, 2016. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-18-64/california-counties?period=2016. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 aged 18 to 64, 2016. 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-18-64/california-counties?period=2016.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 aged 18 to 64, 2016 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-18-64/california-counties?period=2016 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_by_2016,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 aged 18 to 64, 2016}},
  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-18-64/california-counties?period=2016. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 18 to 64 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 aged 18 to 64, 2016
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-18-64/california-counties?period=2016
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/california-counties?period=2016.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 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 California by population aged 18 to 64 using official data, and cite the source.
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Questions

Which county has the highest population aged 18 to 64?

San Francisco County, with 71.9% in 2016, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Sierra County, with 54.5% in 2016.

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 18 to 64 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 aged 18 to 64: other rankings

Counties in California: more rankings