Data / Rankings / Population density / Counties in Idaho

Counties in Idaho by population density, 2025

Ada County had the highest population density of 44 counties in 2025, at 200.4 inhabitants per km². Clark County had the lowest, at 0.2 inhabitants per km². The median was 3.9 inhabitants per km² and the figure for Idaho was 9.5 inhabitants per km². Source: the U.S. Census Bureau.

Highest200.4Ada County
Lowest0.2Clark County
Median3.944 counties
Idaho9.5History

All counties, 2025

CSVChart (SVG)

Ada CountyAda County: 200.4 inhabitants per km²200.4Canyon CountyCanyon County: 180.9 inhabitants per km²180.9Kootenai CountyKootenai County: 59.8 inhabitants per km²59.8Madison CountyMadison County: 45.4 inhabitants per km²45.4Bannock CountyBannock County: 31.8 inhabitants per km²31.8Bonneville CountyBonneville County: 28.1 inhabitants per km²28.1Payette CountyPayette County: 26.4 inhabitants per km²26.4Twin Falls CountyTwin Falls County: 19.6 inhabitants per km²19.6Nez Perce CountyNez Perce County: 19.5 inhabitants per km²19.5Jerome CountyJerome County: 17 inhabitants per km²17Gem CountyGem County: 15 inhabitants per km²15Latah CountyLatah County: 15 inhabitants per km²15Jefferson CountyJefferson County: 12.5 inhabitants per km²12.5Bonner CountyBonner County: 12.1 inhabitants per km²12.1Minidoka CountyMinidoka County: 11.7 inhabitants per km²11.7Teton CountyTeton County: 11.4 inhabitants per km²11.4Bingham CountyBingham County: 9.4 inhabitants per km²9.4Franklin CountyFranklin County: 9.3 inhabitants per km²9.3Gooding CountyGooding County: 8.7 inhabitants per km²8.7Benewah CountyBenewah County: 5.2 inhabitants per km²5.2Boundary CountyBoundary County: 4.3 inhabitants per km²4.3Cassia CountyCassia County: 4 inhabitants per km²4Blaine CountyBlaine County: 3.7 inhabitants per km²3.7Elmore CountyElmore County: 3.7 inhabitants per km²3.7Washington CountyWashington County: 3.1 inhabitants per km²3.1Lewis CountyLewis County: 3 inhabitants per km²3Fremont CountyFremont County: 2.9 inhabitants per km²2.9Bear Lake CountyBear Lake County: 2.7 inhabitants per km²2.7Power CountyPower County: 2.3 inhabitants per km²2.3Shoshone CountyShoshone County: 2.1 inhabitants per km²2.1Lincoln CountyLincoln County: 1.8 inhabitants per km²1.8Boise CountyBoise County: 1.7 inhabitants per km²1.7Oneida CountyOneida County: 1.6 inhabitants per km²1.6Caribou CountyCaribou County: 1.6 inhabitants per km²1.6Clearwater CountyClearwater County: 1.4 inhabitants per km²1.4Adams CountyAdams County: 1.4 inhabitants per km²1.4Valley CountyValley County: 1.4 inhabitants per km²1.4Idaho CountyIdaho County: 0.8 inhabitants per km²0.8Lemhi CountyLemhi County: 0.7 inhabitants per km²0.7Owyhee CountyOwyhee County: 0.6 inhabitants per km²0.6Butte CountyButte County: 0.5 inhabitants per km²0.5Camas CountyCamas County: 0.5 inhabitants per km²0.5Custer CountyCuster County: 0.4 inhabitants per km²0.4Clark CountyClark County: 0.2 inhabitants per km²0.2
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2025
inhabitants per km²		Change on 2024
1Ada County200.4+2%
2Canyon County180.9+2.9%
3Kootenai County59.8+1.8%
4Madison County45.4+0.4%
5Bannock County31.8+0.7%
6Bonneville County28.1+1.5%
7Payette County26.4+0.5%
8Twin Falls County19.6+1.1%
9Nez Perce County19.50%
10Jerome County17+0.3%
11Gem County15+1.5%
12Latah County15+0.2%
13Jefferson County12.5+1.3%
14Bonner County12.1+1.4%
15Minidoka County11.7+0.8%
16Teton County11.4+1.1%
17Bingham County9.4+0.4%
18Franklin County9.3+1.4%
19Gooding County8.7+0.3%
20Benewah County5.2+0.2%
21Boundary County4.3+1%
22Cassia County4+0.7%
23Blaine County3.7-0.7%
24Elmore County3.7-0.4%
25Washington County3.1+0.8%
26Lewis County3-0.2%
27Fremont County2.9-1%
28Bear Lake County2.7+0.4%
29Power County2.3-1%
30Shoshone County2.1+0.7%
31Lincoln County1.8-0.5%
32Boise County1.7+0.5%
33Oneida County1.6+1.4%
34Caribou County1.6+0.4%
35Clearwater County1.4-0.3%
36Adams County1.4+0.1%
37Valley County1.4+0.1%
38Idaho County0.80%
39Lemhi County0.7+0.8%
40Owyhee County0.6-0.9%
41Butte County0.5+1.9%
42Camas County0.5+2.2%
43Custer County0.4+1.4%
44Clark County0.20%

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?

Ada County, with 200.4 inhabitants per km² in 2025, according to the U.S. Census Bureau.

Which county has the lowest population density?

Clark County, with 0.2 inhabitants per km² in 2025.

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 Idaho: more rankings