Counties in Washington by population aged 18 to 64

Whitman County had the highest population aged 18 to 64 of 39 counties in 2019, at 72.9%. Jefferson County had the lowest, at 49.6%. The median was 57.1% and the figure for Washington was 62.1%. Source: the U.S. Census Bureau.

Highest72.9Whitman County

Lowest49.6Jefferson County

Median57.139 counties

Washington62.1History

Map of counties, 2019

Under 52
52 to 56
56 to 57
57 to 58
58 to 61
61 and over

%, 2019. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2019

%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

Rank	Counties	2019 (%)	Change on 2018
1	Whitman County	72.9	-0.2 pts
2	King County	66.5	-0.1 pts
3	Snohomish County	63.2	-0.3 pts
4	Kittitas County	63.1	-0.8 pts
5	Pierce County	62.6	-0.2 pts
6	Whatcom County	62.1	-0.3 pts
7	Spokane County	61.1	-0.2 pts
8	Kitsap County	61.1	-0.3 pts
9	Skamania County	60.7	-0.8 pts
10	Thurston County	60.5	-0.4 pts
11	Clark County	60.5	-0.1 pts
12	Walla Walla County	59.9	-0.5 pts
13	Franklin County	58.7	0 pts
14	Benton County	58.2	-0.3 pts
15	Grays Harbor County	58	-0.5 pts
16	Cowlitz County	57.7	-0.1 pts
17	Mason County	57.6	-0.6 pts
18	Chelan County	57.4	-0.3 pts
19	Yakima County	57.3	-0 pts
20	Klickitat County	57.1	-0.2 pts
21	Douglas County	57.1	-0.3 pts
22	Grant County	57	-0.1 pts
23	Lewis County	56.7	-0.4 pts
24	Skagit County	56.4	-0.5 pts
25	Island County	56.2	-0.5 pts
26	Asotin County	56.1	-0.4 pts
27	Stevens County	54.9	-0.2 pts
28	Adams County	54.6	-0.1 pts
29	Okanogan County	54.5	-0.4 pts
30	Columbia County	53.9	0 pts
31	Pend Oreille County	53.8	-0.9 pts
32	Lincoln County	52.4	-0.5 pts
33	San Juan County	52.3	-0.6 pts
34	Clallam County	52.3	-0.6 pts
35	Garfield County	52.2	-0.1 pts
36	Ferry County	51.9	-0.9 pts
37	Pacific County	51.9	-0.6 pts
38	Wahkiakum County	51.6	-0.8 pts
39	Jefferson County	49.6	-0.9 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, 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 Washington 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/washington-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 Washington 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/washington-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 Washington 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/washington-counties?period=2019 (Accessed: 12 October 2026).

BibTeX

@misc{census_counties_in_washington_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 Washington 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/washington-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 Washington 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/washington-counties?period=2019
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/washington-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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Questions

Which county has the highest population aged 18 to 64?

Whitman County, with 72.9% in 2019, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Jefferson County, with 49.6% 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.