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

Counties in Washington by population aged 18 to 64

Whitman County had the highest population aged 18 to 64 of 39 counties in 2020, at 72.3%. Jefferson County had the lowest, at 48.6%. The median was 56.8% and the figure for Washington was 61.8%. Source: the U.S. Census Bureau.

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Highest72.3Whitman County
Lowest48.6Jefferson County
Median56.839 counties
Washington61.8History

Map of counties, 2020

Adams County: 54.5 %Asotin County: 55.3 %Benton County: 58 %Chelan County: 56.9 %Clallam County: 51.4 %Clark County: 60.2 %Columbia County: 53.9 %Cowlitz County: 57.5 %Douglas County: 56.9 %Ferry County: 51.5 %Franklin County: 58.4 %Garfield County: 51.3 %Grant County: 56.7 %Grays Harbor County: 57.3 %Island County: 55.6 %Jefferson County: 48.6 %King County: 66.3 %Kitsap County: 60.6 %Kittitas County: 64.5 %Klickitat County: 56.8 %Lewis County: 56.2 %Lincoln County: 52 %Mason County: 57.1 %Okanogan County: 54 %Pacific County: 51.3 %Pend Oreille County: 52.8 %Pierce County: 62.2 %San Juan County: 51.4 %Skagit County: 56 %Skamania County: 59.6 %Snohomish County: 62.8 %Spokane County: 60.8 %Stevens County: 54 %Thurston County: 60.1 %Wahkiakum County: 51 %Walla Walla County: 59.3 %Whatcom County: 61.8 %Whitman County: 72.3 %Yakima County: 56.8 %
  • Under 52
  • 52 to 55
  • 55 to 57
  • 57 to 58
  • 58 to 61
  • 61 and over
%, 2020. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2020

Whitman County: 72.3 %Whitman County72.3King County: 66.3 %King County66.3Kittitas County: 64.5 %Kittitas County64.5Snohomish County: 62.8 %Snohomish County62.8Pierce County: 62.2 %Pierce County62.2Whatcom County: 61.8 %Whatcom County61.8Spokane County: 60.8 %Spokane County60.8Kitsap County: 60.6 %Kitsap County60.6Clark County: 60.2 %Clark County60.2Thurston County: 60.1 %Thurston County60.1Skamania County: 59.6 %Skamania County59.6Walla Walla County: 59.3 %Walla Walla County59.3Franklin County: 58.4 %Franklin County58.4Benton County: 58 %Benton County58Cowlitz County: 57.5 %Cowlitz County57.5Grays Harbor County: 57.3 %Grays Harbor County57.3Mason County: 57.1 %Mason County57.1Douglas County: 56.9 %Douglas County56.9Chelan County: 56.9 %Chelan County56.9Yakima County: 56.8 %Yakima County56.8Klickitat County: 56.8 %Klickitat County56.8Grant County: 56.7 %Grant County56.7Lewis County: 56.2 %Lewis County56.2Skagit County: 56 %Skagit County56Island County: 55.6 %Island County55.6Asotin County: 55.3 %Asotin County55.3Adams County: 54.5 %Adams County54.5Okanogan County: 54 %Okanogan County54Stevens County: 54 %Stevens County54Columbia County: 53.9 %Columbia County53.9Pend Oreille County: 52.8 %Pend Oreille County52.8Lincoln County: 52 %Lincoln County52Ferry County: 51.5 %Ferry County51.5Clallam County: 51.4 %Clallam County51.4San Juan County: 51.4 %San Juan County51.4Pacific County: 51.3 %Pacific County51.3Garfield County: 51.3 %Garfield County51.3Wahkiakum County: 51 %Wahkiakum County51Jefferson County: 48.6 %Jefferson County48.6Whitman County: 72.3 %Whitman County72.3King County: 66.3 %King County66.3Kittitas County: 64.5 %Kittitas County64.5Snohomish County: 62.8 %Snohomish County62.8Pierce County: 62.2 %Pierce County62.2Whatcom County: 61.8 %Whatcom County61.8Spokane County: 60.8 %Spokane County60.8Kitsap County: 60.6 %Kitsap County60.6Clark County: 60.2 %Clark County60.2Thurston County: 60.1 %Thurston County60.1Skamania County: 59.6 %Skamania County59.6Walla Walla County: 59.3 %Walla Walla County59.3Franklin County: 58.4 %Franklin County58.4Benton County: 58 %Benton County58Cowlitz County: 57.5 %Cowlitz County57.5Grays Harbor County: 57.3 %Grays Harbor County57.3Mason County: 57.1 %Mason County57.1Douglas County: 56.9 %Douglas County56.9Chelan County: 56.9 %Chelan County56.9Yakima County: 56.8 %Yakima County56.8Klickitat County: 56.8 %Klickitat County56.8Grant County: 56.7 %Grant County56.7Lewis County: 56.2 %Lewis County56.2Skagit County: 56 %Skagit County56Island County: 55.6 %Island County55.6Asotin County: 55.3 %Asotin County55.3Adams County: 54.5 %Adams County54.5Okanogan County: 54 %Okanogan County54Stevens County: 54 %Stevens County54Columbia County: 53.9 %Columbia County53.9Pend Oreille County: 52.8 %Pend Oreille County52.8Lincoln County: 52 %Lincoln County52Ferry County: 51.5 %Ferry County51.5Clallam County: 51.4 %Clallam County51.4San Juan County: 51.4 %San Juan County51.4Pacific County: 51.3 %Pacific County51.3Garfield County: 51.3 %Garfield County51.3Wahkiakum County: 51 %Wahkiakum County51Jefferson County: 48.6 %Jefferson County48.6
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2020 (%)Change on 2019
1Whitman County72.3-0.6 pts
2King County66.3-0.1 pts
3Kittitas County64.5+1.4 pts
4Snohomish County62.8-0.4 pts
5Pierce County62.2-0.4 pts
6Whatcom County61.8-0.4 pts
7Spokane County60.8-0.3 pts
8Kitsap County60.6-0.5 pts
9Clark County60.2-0.2 pts
10Thurston County60.1-0.4 pts
11Skamania County59.6-1.1 pts
12Walla Walla County59.3-0.7 pts
13Franklin County58.4-0.3 pts
14Benton County58-0.2 pts
15Cowlitz County57.5-0.3 pts
16Grays Harbor County57.3-0.7 pts
17Mason County57.1-0.6 pts
18Douglas County56.9-0.1 pts
19Chelan County56.9-0.5 pts
20Yakima County56.8-0.4 pts
21Klickitat County56.8-0.3 pts
22Grant County56.7-0.3 pts
23Lewis County56.2-0.5 pts
24Skagit County56-0.5 pts
25Island County55.6-0.6 pts
26Asotin County55.3-0.8 pts
27Adams County54.5-0.1 pts
28Okanogan County54-0.5 pts
29Stevens County54-0.9 pts
30Columbia County53.9+0.1 pts
31Pend Oreille County52.8-1 pts
32Lincoln County52-0.4 pts
33Ferry County51.5-0.5 pts
34Clallam County51.4-0.8 pts
35San Juan County51.4-0.8 pts
36Pacific County51.3-0.6 pts
37Garfield County51.3-0.9 pts
38Wahkiakum County51-0.6 pts
39Jefferson County48.6-1 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 Washington by population aged 18 to 64, 2020) [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 Washington by population aged 18 to 64, 2020. 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/washington-counties?period=2020. 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 Washington by population aged 18 to 64, 2020. 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/washington-counties?period=2020.

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 Washington by population aged 18 to 64, 2020 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-18-64/washington-counties?period=2020 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_washington_by_2020,
  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 Washington by population aged 18 to 64, 2020}},
  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/washington-counties?period=2020. 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 Washington by population aged 18 to 64, 2020
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/washington-counties?period=2020
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/washington-counties?period=2020.
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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Questions

Which county has the highest population aged 18 to 64?

Whitman County, with 72.3% in 2020, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Jefferson County, with 48.6% in 2020.

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 Washington: more rankings