Data / Rankings / Population density / Counties in Washington

Counties in Washington by population density

King County had the highest population density of 39 counties in 2023, at 416.6 inhabitants per km². Garfield County had the lowest, at 1.3 inhabitants per km². The median was 14.8 inhabitants per km² and the figure for Washington was 45.5 inhabitants per km². Source: the U.S. Census Bureau.

Highest416.6King County
Lowest1.3Garfield County
Median14.839 counties
Washington45.5History

All counties, 2023

CSVChart (SVG)

King CountyKing County: 416.6 inhabitants per km²416.6Clark CountyClark County: 320.6 inhabitants per km²320.6Kitsap CountyKitsap County: 271.1 inhabitants per km²271.1Pierce CountyPierce County: 215.6 inhabitants per km²215.6Thurston CountyThurston County: 159.9 inhabitants per km²159.9Island CountyIsland County: 159.5 inhabitants per km²159.5Snohomish CountySnohomish County: 157 inhabitants per km²157Spokane CountySpokane County: 120.9 inhabitants per km²120.9Benton CountyBenton County: 49 inhabitants per km²49Whatcom CountyWhatcom County: 42.6 inhabitants per km²42.6San Juan CountySan Juan County: 41.2 inhabitants per km²41.2Cowlitz CountyCowlitz County: 38.2 inhabitants per km²38.2Franklin CountyFranklin County: 31 inhabitants per km²31Skagit CountySkagit County: 29.3 inhabitants per km²29.3Mason CountyMason County: 27.7 inhabitants per km²27.7Yakima CountyYakima County: 23.1 inhabitants per km²23.1Walla Walla CountyWalla Walla County: 18.8 inhabitants per km²18.8Clallam CountyClallam County: 17.2 inhabitants per km²17.2Grays Harbor CountyGrays Harbor County: 15.7 inhabitants per km²15.7Grant CountyGrant County: 14.8 inhabitants per km²14.8Lewis CountyLewis County: 13.9 inhabitants per km²13.9Asotin CountyAsotin County: 13.7 inhabitants per km²13.7Chelan CountyChelan County: 10.6 inhabitants per km²10.6Pacific CountyPacific County: 10 inhabitants per km²10Douglas CountyDouglas County: 9.5 inhabitants per km²9.5Whitman CountyWhitman County: 8.5 inhabitants per km²8.5Kittitas CountyKittitas County: 8 inhabitants per km²8Stevens CountyStevens County: 7.6 inhabitants per km²7.6Jefferson CountyJefferson County: 7.2 inhabitants per km²7.2Wahkiakum CountyWahkiakum County: 7 inhabitants per km²7Klickitat CountyKlickitat County: 4.9 inhabitants per km²4.9Adams CountyAdams County: 4.2 inhabitants per km²4.2Pend Oreille CountyPend Oreille County: 4 inhabitants per km²4Okanogan CountyOkanogan County: 3.2 inhabitants per km²3.2Skamania 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

RankCounties2023
inhabitants per km²		Change on 2022
1King County416.6+0.8%
2Clark County320.6+1%
3Kitsap County271.1-0.2%
4Pierce County215.6+0.4%
5Thurston County159.9+0.2%
6Island County159.5-0.6%
7Snohomish County157+0.9%
8Spokane County120.9+0.5%
9Benton County49+1.4%
10Whatcom County42.6+0.9%
11San Juan County41.2-0.6%
12Cowlitz County38.2+0.8%
13Franklin County31+1.3%
14Skagit County29.3+0.3%
15Mason County27.7+0.8%
16Yakima County23.1+0.3%
17Walla Walla County18.8-0.4%
18Clallam County17.2-0.1%
19Grays Harbor County15.7+0.6%
20Grant County14.8+1.7%
21Lewis County13.9+1.2%
22Asotin County13.70%
23Chelan County10.6+0.4%
24Pacific County10+0.4%
25Douglas County9.5+1.6%
26Whitman County8.5+0.1%
27Kittitas County8+0.9%
28Stevens County7.6+1.3%
29Jefferson County7.2+0.3%
30Wahkiakum County7+1.5%
31Klickitat County4.9+1.6%
32Adams County4.2+0.3%
33Pend Oreille County4+1.6%
34Okanogan County3.2+1.4%
35Skamania County2.9+1.4%
36Lincoln County2+1.1%
37Columbia County1.8+1.1%
38Ferry County1.3+0.7%
39Garfield County1.3+0.1%

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 416.6 inhabitants per km² in 2023, according to the U.S. Census Bureau.

Which county has the lowest population density?

Garfield County, with 1.3 inhabitants per km² in 2023.

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