Data / Rankings / Population density / Counties in Washington

Counties in Washington by population density

King County had the highest population density of 39 counties in 2024, at 423 inhabitants per km². Garfield County had the lowest, at 1.3 inhabitants per km². The median was 15.1 inhabitants per km² and the figure for Washington was 46.1 inhabitants per km². Source: the U.S. Census Bureau.

Highest423King County
Lowest1.3Garfield County
Median15.139 counties
Washington46.1History

All counties, 2024

CSVChart (SVG)

King CountyKing County: 423 inhabitants per km²423Clark CountyClark County: 323.3 inhabitants per km²323.3Kitsap CountyKitsap County: 274.3 inhabitants per km²274.3Pierce CountyPierce County: 217.5 inhabitants per km²217.5Thurston CountyThurston County: 161.5 inhabitants per km²161.5Snohomish CountySnohomish County: 159.3 inhabitants per km²159.3Island CountyIsland County: 159.1 inhabitants per km²159.1Spokane CountySpokane County: 121.6 inhabitants per km²121.6Benton CountyBenton County: 49.7 inhabitants per km²49.7Whatcom CountyWhatcom County: 43 inhabitants per km²43San Juan CountySan Juan County: 41.2 inhabitants per km²41.2Cowlitz CountyCowlitz County: 38.5 inhabitants per km²38.5Franklin CountyFranklin County: 31.5 inhabitants per km²31.5Skagit CountySkagit County: 29.5 inhabitants per km²29.5Mason CountyMason County: 28.1 inhabitants per km²28.1Yakima CountyYakima County: 23.3 inhabitants per km²23.3Walla Walla CountyWalla Walla County: 18.9 inhabitants per km²18.9Clallam CountyClallam County: 17.3 inhabitants per km²17.3Grays Harbor CountyGrays Harbor County: 15.8 inhabitants per km²15.8Grant CountyGrant County: 15.1 inhabitants per km²15.1Lewis CountyLewis County: 14 inhabitants per km²14Asotin CountyAsotin County: 13.7 inhabitants per km²13.7Chelan CountyChelan County: 10.8 inhabitants per km²10.8Pacific CountyPacific County: 10 inhabitants per km²10Douglas CountyDouglas County: 9.7 inhabitants per km²9.7Whitman CountyWhitman County: 8.6 inhabitants per km²8.6Kittitas CountyKittitas County: 8.1 inhabitants per km²8.1Stevens CountyStevens County: 7.7 inhabitants per km²7.7Jefferson CountyJefferson County: 7.3 inhabitants per km²7.3Wahkiakum CountyWahkiakum County: 7.1 inhabitants per km²7.1Klickitat CountyKlickitat County: 5 inhabitants per km²5Adams CountyAdams County: 4.3 inhabitants per km²4.3Pend Oreille CountyPend Oreille County: 4 inhabitants per km²4Okanogan CountyOkanogan County: 3.3 inhabitants per km²3.3Skamania CountySkamania County: 2.9 inhabitants per km²2.9Lincoln CountyLincoln County: 2 inhabitants per km²2Columbia CountyColumbia County: 1.8 inhabitants per km²1.8Ferry CountyFerry County: 1.3 inhabitants per km²1.3Garfield CountyGarfield County: 1.3 inhabitants per km²1.3
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2024
inhabitants per km²		Change on 2023
1King County423+1.5%
2Clark County323.3+0.8%
3Kitsap County274.3+1.2%
4Pierce County217.5+0.9%
5Thurston County161.5+1%
6Snohomish County159.3+1.5%
7Island County159.1-0.2%
8Spokane County121.6+0.5%
9Benton County49.7+1.5%
10Whatcom County43+0.9%
11San Juan County41.2-0%
12Cowlitz County38.5+0.8%
13Franklin County31.5+1.7%
14Skagit County29.5+0.6%
15Mason County28.1+1.4%
16Yakima County23.3+0.6%
17Walla Walla County18.9+0.6%
18Clallam County17.3+0.5%
19Grays Harbor County15.8+0.6%
20Grant County15.1+1.7%
21Lewis County14+1%
22Asotin County13.7+0.2%
23Chelan County10.8+1.3%
24Pacific County10+0.2%
25Douglas County9.7+1.5%
26Whitman County8.6+0.6%
27Kittitas County8.1+0.7%
28Stevens County7.7+0.6%
29Jefferson County7.3+0.5%
30Wahkiakum County7.1+1%
31Klickitat County5+1.7%
32Adams County4.3+2%
33Pend Oreille County40%
34Okanogan County3.3+2.1%
35Skamania County2.9+0.1%
36Lincoln County2+0.8%
37Columbia County1.8-0.4%
38Ferry County1.3+0.8%
39Garfield County1.3+1.9%

Other periods

About this ranking

Resident population divided by land area in km². World Bank figures use mid-year population and land area excluding inland water.

United States: Census Bureau population estimates for 1 July divided by land area (water excluded) from the latest Census Gazetteer files. US tables often give people per square mile; multiply persons per km² by 2.59 to compare.

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 resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-09.

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Questions

Which county has the highest population density?

King County, with 423 inhabitants per km² in 2024, according to the U.S. Census Bureau.

Which county has the lowest population density?

Garfield County, with 1.3 inhabitants per km² in 2024.

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 resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². Retrieved 2026-10-09.

Population density: other rankings

Counties in Washington: more rankings