• county
  • FIPS 19103
  • Largest town: Iowa City

Johnson County, Iowa

Johnson County had 160,080 residents in the Census Vintage 2024 estimate, on 613.0 square miles of land. It ranks 4th of 99 in Iowa by population and 20th by land area.

Population
160,080
#4 of 99 in Iowa · #438 in US
Area
613.0 sq mi
#20 of 99 in Iowa · #1,577 in US
Density
261 / sq mi
#4 of 99 in Iowa · #481 in US
Median household income
$74,665
#25 of 99 in Iowa · #691 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Johnson County within Iowa. Pin: Des Moines.

Measure from here

Tools and pages that start from Johnson County

Johnson County population, land area and income

Johnson County had 160,080 residents in the Census Vintage 2024 estimate, on 613.0 square miles of land. It ranks 4th of 99 in Iowa by population and 20th by land area. That works out to 261.1 people per square mile, 2.7 times the US average of 96.3, and in the top quarter nationally.

The median county-equivalent in Iowa has 15,008 residents, so Johnson County is 10.7 times that size.

Its SAIPE 2023 median household income of $74,665 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

160,080

3144th1st

438th of 3,144 (US)

Land area

613 sq mi

3144th1st

1577th of 3,144 (US)

Density

261.1 / sq mi

3144th1st

481st of 3,144 (US)

Median household income

$74,665

3143rd1st

691st of 3,143 (US)

Rank within Iowa (99)

Population

160,080

99th1st

4th of 99 (IA)

Land area

613 sq mi

99th1st

20th of 99 (IA)

Density

261.1 / sq mi

99th1st

4th of 99 (IA)

Median household income

$74,665

99th1st

25th of 99 (IA)

How Johnson County's population changed since 2020

Johnson County gained 7,028 residents between the July 2020 and July 2024 estimates, a rise of 4.6%. That ranks 4th of 99 in Iowa for growth. The median Iowa county changed by -0.6%, and the state as a whole by +1.6%.

Since the April 2020 estimates base, Johnson County recorded 7,098 births and 3,798 deaths, a natural change of +3,300. Net international migration added +4,867 and net domestic migration, people moving to or from other US counties, came to -1,006. The largest single component was international migration, which added 4,867 people.

153.1k2020155.0k2021156.8k2022158.2k2023160.1k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
7,098
Deaths
3,798
Net international migration
+4,867
Net domestic migration
-1,006
Change, July 2023 to July 2024
+1,878

Where Johnson County is

The Census internal point of Johnson County is at 41.670700, -91.590500. It sits in UTM zone 15N. The map shades Iowa's 99 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Johnson County outlined. Dots are towns of 1,000+ people with residents in it.

Monroe County: -2.9%Worth County: -1.7%Buena Vista County: +0.0%Jasper County: +0.8%Van Buren County: -0.0%Hardin County: -2.2%Ida County: -3.1%Marshall County: +0.8%Fayette County: -1.5%Ringgold County: -0.8%Wapello County: +1.0%Webster County: -0.2%Adams County: -2.8%Buchanan County: +0.6%Cerro Gordo County: -1.2%Lucas County: +1.6%Emmet County: -1.9%Floyd County: -3.8%Crawford County: -0.7%Linn County: +0.6%Montgomery County: -2.6%Polk County: +4.7%Cherokee County: +0.0%Bremer County: +1.3%Grundy County: +0.5%Adair County: -0.8%Cedar County: -1.4%Story County: +3.9%Mahaska County: -0.6%Davis County: +0.9%Clay County: +0.8%Johnson County: +4.6%Greene County: -1.0%Palo Alto County: -2.0%Benton County: +1.0%Cass County: -0.7%Wright County: -1.5%Audubon County: -2.1%Henry County: -5.3%Boone County: +0.1%Appanoose County: -1.4%Washington County: +0.4%Chickasaw County: -2.2%Poweshiek County: -0.9%Osceola County: -2.6%Wayne County: +1.8%Mitchell County: +0.4%Jefferson County: +0.5%Union County: -1.4%Butler County: -1.2%Hancock County: -1.3%Marion County: +1.9%Delaware County: +0.9%Humboldt County: +0.2%Sioux County: +1.8%Des Moines County: -1.1%O'Brien County: +0.8%Clayton County: -0.6%Black Hawk County: +1.0%Winnebago County: -2.6%Harrison County: +0.4%Decatur County: -1.0%Pocahontas County: -0.9%Lyon County: +3.8%Iowa County: -1.4%Franklin County: +0.3%Dickinson County: +2.2%Madison County: +3.2%Allamakee County: +0.8%Jones County: +2.2%Carroll County: -1.6%Kossuth County: -2.6%Hamilton County: -1.0%Howard County: -1.4%Page County: -1.1%Guthrie County: +1.5%Tama County: -1.8%Monona County: -3.6%Clarke County: -2.1%Lee County: -3.4%Mills County: +2.1%Sac County: -2.7%Scott County: +0.6%Keokuk County: -1.6%Jackson County: -0.3%Warren County: +7.1%Calhoun County: -1.9%Shelby County: +0.8%Fremont County: -1.1%Dubuque County: -0.1%Louisa County: -1.8%Taylor County: -0.6%Woodbury County: +1.2%Clinton County: -0.9%Winneshiek County: -1.6%Pottawattamie County: -0.1%Plymouth County: +0.5%Muscatine County: -2.4%Dallas County: +14.7%
Change 2020 to 2024
  1. < -1.9%
  2. < -1.0%
  3. < +0.0%
  4. < +0.9%
  5. ≥ +0.9%
no data

Orange pin: Johnson County internal point. Dark pin: Des Moines.

Internal point

Decimal
41.670700, -91.590500
DMS
41°40'14.52"N 91°35'25.80"W
UTM
15N 617332.7E 4614175.1N
Geohash
9zqv5ccv6
Plus code
86HCMCC5+7Q

Towns in Johnson County

8 incorporated places of 1,000+ people have residents in Johnson County, 135,192 people together, or 84% of the county. Each figure counts only the part of the town inside Johnson County; towns marked "part" extend into another county. The largest is Iowa City with 76,710.

  1. 01Iowa City76,710
  2. 02Coralville23,959
  3. 03North Liberty21,904
  4. 04Tiffin6,695
  5. 05Solon3,284
  6. 06Lone Tree1,341
  7. 07University Heights1,188
  8. 08West Branch (part)111
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Johnson County

The Census 2024 county adjacency file lists 7 neighbors for Johnson County. The most populous is Linn County, IA, with 231,762 residents. Distances run between Census internal points in a straight line.

Distance to Des Moines and the nearest big city

Des Moines is 104.1 miles W of Johnson County's internal point in a straight line. The nearest place of 100,000 or more is Cedar Rapids, IA (population 137,904), 20.8 miles away. The nearest place of 10,000 or more is Coralville, IA (population 23,959), 2.0 miles away.

Johnson County FIPS code

The FIPS code of Johnson County is 19103: state code 19 for Iowa plus county code 103. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $74,665.

Questions people ask

What is the population of Johnson County, Iowa?

The Census Vintage 2024 estimate for July 1, 2024 is 160,080. That is up 7,028 people (4.6%) from the July 2020 estimate of 153,052.

What is the FIPS code of Johnson County?

19103. The first two digits (19) are Iowa; the last three (103) identify the county.

What is the largest town in Johnson County?

Iowa City, with 76,710 residents inside Johnson County in 2024.

Which counties border Johnson County?

7 county-equivalents border it in the Census 2024 adjacency file: Linn County, IA; Muscatine County, IA; Benton County, IA; Washington County, IA; Cedar County, IA; Iowa County, IA; Louisa County, IA.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.