• county
  • FIPS 17031
  • Largest town: Chicago

Cook County, Illinois

Cook County had 5,182,617 residents in the Census Vintage 2024 estimate, on 944.9 square miles of land. It is the most populous of Illinois's 102 county-equivalents.

Population
5,182,617
#1 of 102 in Illinois · #2 in US
Area
944.9 sq mi
#6 of 102 in Illinois · #751 in US
Density
5,485 / sq mi
#1 of 102 in Illinois · #17 in US
Median household income
$80,547
#15 of 102 in Illinois · #463 in US

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

Cook County within Illinois. Pin: Springfield.

Measure from here

Tools and pages that start from Cook County

Cook County population, land area and income

Cook County had 5,182,617 residents in the Census Vintage 2024 estimate, on 944.9 square miles of land. It is the most populous of Illinois's 102 county-equivalents. That works out to 5,484.7 people per square mile, 57.0 times the US average of 96.3, and in the top tenth nationally.

The median county-equivalent in Illinois has 24,447 residents, so Cook County is 212.0 times that size.

Its SAIPE 2023 median household income of $80,547 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

5,182,617

3144th1st

2nd of 3,144 (US)

Land area

945 sq mi

3144th1st

751st of 3,144 (US)

Density

5,484.7 / sq mi

3144th1st

17th of 3,144 (US)

Median household income

$80,547

3143rd1st

463rd of 3,143 (US)

Rank within Illinois (102)

Population

5,182,617

102nd1st

1st of 102 (IL)

Land area

945 sq mi

102nd1st

6th of 102 (IL)

Density

5,484.7 / sq mi

102nd1st

1st of 102 (IL)

Median household income

$80,547

102nd1st

15th of 102 (IL)

How Cook County's population changed since 2020

Cook County lost 84,455 residents between the July 2020 and July 2024 estimates, a drop of 1.6%. That ranks 49th of 102 in Illinois for growth. The median Illinois county changed by -1.7%, and the state as a whole by -0.7%.

Since the April 2020 estimates base, Cook County recorded 225,212 births and 196,304 deaths, a natural change of +28,908. Net international migration added +166,162 and net domestic migration, people moving to or from other US counties, came to -290,914. The largest single component was domestic migration, which removed 290,914 people.

5.27M20205.19M20215.13M20225.14M20235.18M2024
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
225,212
Deaths
196,304
Net international migration
+166,162
Net domestic migration
-290,914
Change, July 2023 to July 2024
+40,095

Where Cook County is

The Census internal point of Cook County is at 41.894300, -87.645500. It sits in UTM zone 16N. The map shades Illinois's 102 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Cook County outlined. Dots are towns of 1,000+ people with residents in it.

Piatt County: -0.3%Hamilton County: -2.2%Williamson County: -0.1%Edgar County: -2.4%Macoupin County: -2.3%Marshall County: -1.3%Putnam County: +0.0%Richland County: -2.8%Washington County: -1.4%Lee County: -1.5%Douglas County: +0.2%Cook County: -1.6%Effingham County: -0.3%Edwards County: -3.6%Cass County: -2.0%Clay County: -3.4%Knox County: -2.2%LaSalle County: -0.9%Cumberland County: -1.3%Warren County: -3.7%Moultrie County: -0.9%Menard County: -2.5%Fayette County: -1.5%Boone County: -0.0%Lawrence County: -3.2%Marion County: -3.2%Champaign County: +3.0%Clark County: -2.4%Ford County: -0.4%Wayne County: -1.4%Logan County: -1.4%Grundy County: +2.5%Jasper County: -1.8%Crawford County: -1.3%McDonough County: -1.7%Clinton County: +0.5%Perry County: -3.0%Montgomery County: -2.2%Henry County: -2.0%Livingston County: -1.2%Scott County: -3.8%Alexander County: -11.2%Bureau County: -2.2%Brown County: +1.1%Mason County: -3.9%Calhoun County: -4.1%Greene County: -4.3%Coles County: -1.4%Kendall County: +8.2%Lake County: +0.7%Mercer County: -2.2%St. Clair County: -2.3%Wabash County: -3.0%Bond County: -1.7%DuPage County: +0.6%Gallatin County: -5.2%Stephenson County: -3.3%McHenry County: +1.9%White County: -3.0%Saline County: -3.9%Christian County: -2.2%Sangamon County: -1.0%Massac County: -3.6%Macon County: -2.9%Johnson County: -0.0%Jo Daviess County: -2.6%Peoria County: -1.0%DeKalb County: +1.0%Pope County: -1.5%De Witt County: -0.9%Schuyler County: -1.7%Fulton County: -3.1%Ogle County: -0.8%Jersey County: -1.6%Iroquois County: -3.3%Kankakee County: -0.9%Rock Island County: -1.1%Pulaski County: -5.8%Kane County: +0.9%Union County: -2.4%Whiteside County: -1.7%Woodford County: -0.3%Carroll County: -1.5%Adams County: -2.3%Hardin County: -2.6%Madison County: -1.0%Hancock County: -3.1%Monroe County: +0.0%Tazewell County: -1.1%Jackson County: -0.1%Vermilion County: -3.9%Randolph County: -0.6%McLean County: +0.5%Morgan County: -2.6%Shelby County: -1.7%Will County: +1.7%Winnebago County: -0.4%Jefferson County: -2.4%Stark County: -2.2%Henderson County: -4.5%Pike County: -2.6%Franklin County: -1.8%
Change 2020 to 2024
  1. < -3.0%
  2. < -2.2%
  3. < -1.4%
  4. < -0.3%
  5. ≥ -0.3%
no data

Orange pin: Cook County internal point. Dark pin: Springfield.

Internal point

Decimal
41.894300, -87.645500
DMS
41°53'39.48"N 87°38'43.80"W
UTM
16N 446452.7E 4638242.0N
Geohash
dp3wmdd7z
Plus code
86HJV9V3+PR

Towns in Cook County

127 incorporated places of 1,000+ people have residents in Cook County, 5,079,067 people together, or 98% of the county. Each figure counts only the part of the town inside Cook County; towns marked "part" extend into another county. The largest is Chicago with 2,721,308.

  1. 01Chicago2,721,308
  2. 02Cicero82,090
  3. 03Schaumburg77,099
  4. 04Evanston76,006
  5. 05Arlington Heights75,596
  6. 06Palatine65,951
  7. 07Skokie65,850
  8. 08Des Plaines58,832
  9. 09Orland Park (part)57,660
  10. 10Oak Lawn56,531
  11. 11Mount Prospect55,460
  12. 12Berwyn55,152
  13. 13Oak Park52,947
  14. 14Hoffman Estates50,920
  15. 15Glenview47,634
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Cook County

The Census 2024 county adjacency file lists 8 neighbors for Cook County, including 3 across a state line. The most populous is DuPage County, IL, with 937,142 residents. Distances run between Census internal points in a straight line.

Distance to Springfield and the nearest big city

Springfield is 179.7 miles SW of Cook County's internal point in a straight line. The nearest place of 100,000 or more is Chicago, IL (population 2,721,308), 4.5 miles away.

Cook County FIPS code

The FIPS code of Cook County is 17031: state code 17 for Illinois plus county code 031. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $80,547.

Questions people ask

What is the population of Cook County, Illinois?

The Census Vintage 2024 estimate for July 1, 2024 is 5,182,617. That is down 84,455 people (1.6%) from the July 2020 estimate of 5,267,072.

What is the FIPS code of Cook County?

17031. The first two digits (17) are Illinois; the last three (031) identify the county.

What is the largest town in Cook County?

Chicago, with 2,721,308 residents inside Cook County in 2024.

Which counties border Cook County?

8 county-equivalents border it in the Census 2024 adjacency file: DuPage County, IL; Lake County, IL; Will County, IL; Kane County, IL; Lake County, IN; McHenry County, IL; Porter County, IN; Berrien County, MI.

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.