Data / Rankings / Population density / Counties in Washington

Counties in Washington by population density

King County had the highest population density of 39 counties in 2022, at 413.5 inhabitants per km². Garfield County had the lowest, at 1.3 inhabitants per km². The median was 14.6 inhabitants per km² and the figure for Washington was 45.2 inhabitants per km². Source: the U.S. Census Bureau.

Highest413.5King County
Lowest1.3Garfield County
Median14.639 counties
Washington45.2History

All counties, 2022

CSVChart (SVG)

King CountyKing County: 413.5 inhabitants per km²413.5Clark CountyClark County: 317.5 inhabitants per km²317.5Kitsap CountyKitsap County: 271.5 inhabitants per km²271.5Pierce CountyPierce County: 214.7 inhabitants per km²214.7Island CountyIsland County: 160.5 inhabitants per km²160.5Thurston CountyThurston County: 159.5 inhabitants per km²159.5Snohomish CountySnohomish County: 155.6 inhabitants per km²155.6Spokane CountySpokane County: 120.3 inhabitants per km²120.3Benton CountyBenton County: 48.3 inhabitants per km²48.3Whatcom CountyWhatcom County: 42.2 inhabitants per km²42.2San Juan CountySan Juan County: 41.4 inhabitants per km²41.4Cowlitz CountyCowlitz County: 37.9 inhabitants per km²37.9Franklin CountyFranklin County: 30.6 inhabitants per km²30.6Skagit CountySkagit County: 29.3 inhabitants per km²29.3Mason CountyMason County: 27.5 inhabitants per km²27.5Yakima CountyYakima County: 23.1 inhabitants per km²23.1Walla Walla CountyWalla Walla County: 18.9 inhabitants per km²18.9Clallam CountyClallam County: 17.2 inhabitants per km²17.2Grays Harbor CountyGrays Harbor County: 15.7 inhabitants per km²15.7Grant CountyGrant County: 14.6 inhabitants per km²14.6Lewis CountyLewis County: 13.7 inhabitants per km²13.7Asotin CountyAsotin County: 13.7 inhabitants per km²13.7Chelan CountyChelan County: 10.6 inhabitants per km²10.6Pacific CountyPacific County: 10 inhabitants per km²10Douglas CountyDouglas County: 9.4 inhabitants per km²9.4Whitman CountyWhitman County: 8.5 inhabitants per km²8.5Kittitas CountyKittitas County: 8 inhabitants per km²8Stevens CountyStevens County: 7.5 inhabitants per km²7.5Jefferson CountyJefferson County: 7.2 inhabitants per km²7.2Wahkiakum CountyWahkiakum County: 6.9 inhabitants per km²6.9Klickitat CountyKlickitat County: 4.8 inhabitants per km²4.8Adams CountyAdams County: 4.2 inhabitants per km²4.2Pend Oreille CountyPend Oreille County: 3.9 inhabitants per km²3.9Okanogan CountyOkanogan County: 3.2 inhabitants per km²3.2Skamania CountySkamania County: 2.9 inhabitants per km²2.9Lincoln CountyLincoln County: 1.9 inhabitants per km²1.9Columbia 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

RankCounties2022
inhabitants per km²		Change on 2021
1King County413.5+0.5%
2Clark County317.5+0.8%
3Kitsap County271.5+0.4%
4Pierce County214.7-0%
5Island County160.5-1%
6Thurston County159.5+0.1%
7Snohomish County155.6+0.5%
8Spokane County120.3+0.7%
9Benton County48.3+1%
10Whatcom County42.2+1.7%
11San Juan County41.4+0.2%
12Cowlitz County37.9+0.3%
13Franklin County30.6+0.4%
14Skagit County29.3+0.1%
15Mason County27.5+1.4%
16Yakima County23.1-0.1%
17Walla Walla County18.9-0.3%
18Clallam County17.2-1%
19Grays Harbor County15.7+0.3%
20Grant County14.6+0.8%
21Lewis County13.7+0.9%
22Asotin County13.7+0.1%
23Chelan County10.6+0.2%
24Pacific County10+0.3%
25Douglas County9.4+0.6%
26Whitman County8.5+9.8%
27Kittitas County8+3.6%
28Stevens County7.5+1.4%
29Jefferson County7.2+0.1%
30Wahkiakum County6.9+2.3%
31Klickitat County4.8+0.2%
32Adams County4.2+1%
33Pend Oreille County3.9+1.8%
34Okanogan County3.2+0.9%
35Skamania County2.9+2%
36Lincoln County1.9+2.9%
37Columbia County1.80%
38Ferry County1.3+2%
39Garfield County1.3+0.3%

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 413.5 inhabitants per km² in 2022, according to the U.S. Census Bureau.

Which county has the lowest population density?

Garfield County, with 1.3 inhabitants per km² in 2022.

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