Data / Rankings / Population aged 18 to 64 / Counties in California

Counties in California by population aged 18 to 64

San Francisco County had the highest population aged 18 to 64 of 58 counties in 2019, at 71.2%. Sierra County had the lowest, at 52.5%. The median was 60% and the figure for California was 62.9%. Source: the U.S. Census Bureau.

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Highest71.2San Francisco County
Lowest52.5Sierra County
Median6058 counties
California62.9History

Map of counties, 2019

Alameda County: 65.5 %Alpine County: 60.2 %Amador County: 56.4 %Butte County: 60.7 %Calaveras County: 54.7 %Colusa County: 57.5 %Contra Costa County: 61.1 %Del Norte County: 61 %El Dorado County: 57.8 %Fresno County: 59.3 %Glenn County: 57.6 %Humboldt County: 61.7 %Imperial County: 60.1 %Inyo County: 56.5 %Kern County: 60.1 %Kings County: 63 %Lake County: 57.1 %Lassen County: 69.4 %Los Angeles County: 65.1 %Madera County: 58 %Marin County: 57.5 %Mariposa County: 55.2 %Mendocino County: 56.7 %Merced County: 59.4 %Modoc County: 53.6 %Mono County: 64.3 %Monterey County: 60.7 %Napa County: 59.5 %Nevada County: 54.9 %Orange County: 63.5 %Placer County: 57.2 %Plumas County: 53.5 %Riverside County: 60.2 %Sacramento County: 62 %San Benito County: 61.3 %San Bernardino County: 62.1 %San Diego County: 64.1 %San Francisco County: 71.2 %San Joaquin County: 60 %San Luis Obispo County: 60.8 %San Mateo County: 63.5 %Santa Barbara County: 61.9 %Santa Clara County: 65.2 %Santa Cruz County: 63.5 %Shasta County: 56.7 %Sierra County: 52.5 %Siskiyou County: 54.5 %Solano County: 62 %Sonoma County: 59.9 %Stanislaus County: 59.7 %Sutter County: 59.1 %Tehama County: 56.1 %Trinity County: 58.7 %Tulare County: 57.8 %Tuolumne County: 56.5 %Ventura County: 61.1 %Yolo County: 65.3 %Yuba County: 59.8 %
  • Under 56
  • 56 to 58
  • 58 to 60
  • 60 to 61
  • 61 to 63
  • 63 and over
%, 2019. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2019

San Francisco County: 71.2 %San Francisco County71.2Lassen County: 69.4 %Lassen County69.4Alameda County: 65.5 %Alameda County65.5Yolo County: 65.3 %Yolo County65.3Santa Clara County: 65.2 %Santa Clara County65.2Los Angeles County: 65.1 %Los Angeles County65.1Mono County: 64.3 %Mono County64.3San Diego County: 64.1 %San Diego County64.1Orange County: 63.5 %Orange County63.5San Mateo County: 63.5 %San Mateo County63.5Santa Cruz County: 63.5 %Santa Cruz County63.5Kings County: 63 %Kings County63San Bernardino County: 62.1 %San Bernardino County62.1Solano County: 62 %Solano County62Sacramento County: 62 %Sacramento County62Santa Barbara County: 61.9 %Santa Barbara County61.9Humboldt County: 61.7 %Humboldt County61.7San Benito County: 61.3 %San Benito County61.3Contra Costa County: 61.1 %Contra Costa County61.1Ventura County: 61.1 %Ventura County61.1Del Norte County: 61 %Del Norte County61San Luis Obispo County: 60.8 %San Luis Obispo County60.8Butte County: 60.7 %Butte County60.7Monterey County: 60.7 %Monterey County60.7Alpine County: 60.2 %Alpine County60.2Riverside County: 60.2 %Riverside County60.2Imperial County: 60.1 %Imperial County60.1Kern County: 60.1 %Kern County60.1San Joaquin County: 60 %San Joaquin County60Sonoma County: 59.9 %Sonoma County59.9Yuba County: 59.8 %Yuba County59.8Stanislaus County: 59.7 %Stanislaus County59.7Napa County: 59.5 %Napa County59.5Merced County: 59.4 %Merced County59.4Fresno County: 59.3 %Fresno County59.3Sutter County: 59.1 %Sutter County59.1Trinity County: 58.7 %Trinity County58.7Madera County: 58 %Madera County58El Dorado County: 57.8 %El Dorado County57.8Tulare County: 57.8 %Tulare County57.8Glenn County: 57.6 %Glenn County57.6Colusa County: 57.5 %Colusa County57.5Marin County: 57.5 %Marin County57.5Placer County: 57.2 %Placer County57.2Lake County: 57.1 %Lake County57.1Mendocino County: 56.7 %Mendocino County56.7Shasta County: 56.7 %Shasta County56.7Tuolumne County: 56.5 %Tuolumne County56.5Inyo County: 56.5 %Inyo County56.5Amador County: 56.4 %Amador County56.4Tehama County: 56.1 %Tehama County56.1Mariposa County: 55.2 %Mariposa County55.2Nevada County: 54.9 %Nevada County54.9Calaveras County: 54.7 %Calaveras County54.7Siskiyou County: 54.5 %Siskiyou County54.5Modoc County: 53.6 %Modoc County53.6Plumas County: 53.5 %Plumas County53.5Sierra County: 52.5 %Sierra County52.5San Francisco County: 71.2 %San Francisco County71.2Lassen County: 69.4 %Lassen County69.4Alameda County: 65.5 %Alameda County65.5Yolo County: 65.3 %Yolo County65.3Santa Clara County: 65.2 %Santa Clara County65.2Los Angeles County: 65.1 %Los Angeles County65.1Mono County: 64.3 %Mono County64.3San Diego County: 64.1 %San Diego County64.1Orange County: 63.5 %Orange County63.5San Mateo County: 63.5 %San Mateo County63.5Santa Cruz County: 63.5 %Santa Cruz County63.5Kings County: 63 %Kings County63San Bernardino County: 62.1 %San Bernardino County62.1Solano County: 62 %Solano County62Sacramento County: 62 %Sacramento County62Santa Barbara County: 61.9 %Santa Barbara County61.9Humboldt County: 61.7 %Humboldt County61.7San Benito County: 61.3 %San Benito County61.3Contra Costa County: 61.1 %Contra Costa County61.1Ventura County: 61.1 %Ventura County61.1Del Norte County: 61 %Del Norte County61San Luis Obispo County: 60.8 %San Luis Obispo County60.8Butte County: 60.7 %Butte County60.7Monterey County: 60.7 %Monterey County60.7Alpine County: 60.2 %Alpine County60.2Riverside County: 60.2 %Riverside County60.2Imperial County: 60.1 %Imperial County60.1Kern County: 60.1 %Kern County60.1San Joaquin County: 60 %San Joaquin County60Sonoma County: 59.9 %Sonoma County59.9Yuba County: 59.8 %Yuba County59.8Stanislaus County: 59.7 %Stanislaus County59.7Napa County: 59.5 %Napa County59.5Merced County: 59.4 %Merced County59.4Fresno County: 59.3 %Fresno County59.3Sutter County: 59.1 %Sutter County59.1Trinity County: 58.7 %Trinity County58.7Madera County: 58 %Madera County58El Dorado County: 57.8 %El Dorado County57.8Tulare County: 57.8 %Tulare County57.8Glenn County: 57.6 %Glenn County57.6Colusa County: 57.5 %Colusa County57.5Marin County: 57.5 %Marin County57.5Placer County: 57.2 %Placer County57.2Lake County: 57.1 %Lake County57.1Mendocino County: 56.7 %Mendocino County56.7Shasta County: 56.7 %Shasta County56.7Tuolumne County: 56.5 %Tuolumne County56.5Inyo County: 56.5 %Inyo County56.5Amador County: 56.4 %Amador County56.4Tehama County: 56.1 %Tehama County56.1Mariposa County: 55.2 %Mariposa County55.2Nevada County: 54.9 %Nevada County54.9Calaveras County: 54.7 %Calaveras County54.7Siskiyou County: 54.5 %Siskiyou County54.5Modoc County: 53.6 %Modoc County53.6Plumas County: 53.5 %Plumas County53.5Sierra County: 52.5 %Sierra County52.5
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2019 (%)Change on 2018
1San Francisco County71.2-0.3 pts
2Lassen County69.4-0.3 pts
3Alameda County65.5-0.2 pts
4Yolo County65.3-0.3 pts
5Santa Clara County65.20 pts
6Los Angeles County65.1-0.1 pts
7Mono County64.3-0.4 pts
8San Diego County64.1-0.3 pts
9Orange County63.5-0.2 pts
10San Mateo County63.5-0.1 pts
11Santa Cruz County63.5-0.5 pts
12Kings County63-0 pts
13San Bernardino County62.1-0.1 pts
14Solano County62-0.3 pts
15Sacramento County62-0.2 pts
16Santa Barbara County61.9-0.3 pts
17Humboldt County61.7-0.5 pts
18San Benito County61.3-0.1 pts
19Contra Costa County61.1-0.3 pts
20Ventura County61.1-0.3 pts
21Del Norte County61-0.3 pts
22San Luis Obispo County60.8-0.7 pts
23Butte County60.7-0.1 pts
24Monterey County60.7-0.2 pts
25Alpine County60.2-0.5 pts
26Riverside County60.2-0.1 pts
27Imperial County60.1-0.1 pts
28Kern County60.1-0.1 pts
29San Joaquin County60-0 pts
30Sonoma County59.9-0.6 pts
31Yuba County59.8-0.2 pts
32Stanislaus County59.7-0.2 pts
33Napa County59.5-0.3 pts
34Merced County59.40 pts
35Fresno County59.3-0.1 pts
36Sutter County59.1-0.1 pts
37Trinity County58.7-0.4 pts
38Madera County58-0.3 pts
39El Dorado County57.8-0.7 pts
40Tulare County57.8-0 pts
41Glenn County57.60 pts
42Colusa County57.5-0 pts
43Marin County57.5-0.3 pts
44Placer County57.2-0.3 pts
45Lake County57.1-0.3 pts
46Mendocino County56.7-0.6 pts
47Shasta County56.7-0.5 pts
48Tuolumne County56.5-0.8 pts
49Inyo County56.5-0.4 pts
50Amador County56.4-0.8 pts
51Tehama County56.1-0.2 pts
52Mariposa County55.2-0.8 pts
53Nevada County54.9-0.7 pts
54Calaveras County54.7-0.7 pts
55Siskiyou County54.5-0.5 pts
56Modoc County53.6-0.1 pts
57Plumas County53.5-1 pts
58Sierra County52.5-0.6 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, 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 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, 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-18-64/california-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 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, 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-18-64/california-counties?period=2019.

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, 2019 [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=2019 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_by_2019,
  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, 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-18-64/california-counties?period=2019. 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, 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-18-64/california-counties?period=2019
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/california-counties?period=2019.
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 71.2% in 2019, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Sierra County, with 52.5% 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 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