Illinois Demographics
Illinois is the 6th most populous of 52 states in the United States, with 12,812,080 residents across 55,513 square miles. That is about 231 people per square mile. 87% of residents live in urban areas.
At the 2020 census
| Population | 12,812,080 |
|---|---|
| Land area | 55,513 sq mi |
| Density | 231 / sq mi |
| Urban share | 87% |
Data: 2020 Census · American Community Survey 2024
How Illinois compares to the US
We're computing this state's comparison table — check back shortly. Population, land area, and density above are already exact.
Central Location: Illinois
Measured from the state's main population center using 2020 census blocks.
We're computing the drive-time and radius areas around Illinois — check back shortly. Meanwhile you can drop a pin anywhere in the radius tool.
Counties in Illinois
| Name | Population | Sq mi | Per sq mi |
|---|---|---|---|
| Cook County | 5,273,615 | 944.9 | 5,581 |
| DuPage County | 932,877 | 327.8 | 2,846 |
| Lake County | 714,359 | 443.6 | 1,610 |
| Will County | 696,355 | 835.9 | 833 |
| Kane County | 516,522 | 519.4 | 995 |
| McHenry County | 310,229 | 603.4 | 514 |
| Winnebago County | 285,350 | 513.0 | 556 |
| Madison County | 265,859 | 715.5 | 372 |
| St. Clair County | 257,400 | 657.7 | 391 |
| Champaign County | 205,865 | 996.1 | 207 |
| Sangamon County | 196,343 | 868.2 | 226 |
| Peoria County | 181,830 | 618.7 | 294 |
| McLean County | 170,954 | 1,183.2 | 144 |
| Rock Island County | 144,672 | 427.5 | 338 |
| Kendall County | 131,869 | 320.2 | 412 |
| Tazewell County | 131,343 | 646.5 | 203 |
| LaSalle County | 109,658 | 1,135.2 | 97 |
| Kankakee County | 107,502 | 676.5 | 159 |
| Macon County | 103,998 | 580.6 | 179 |
| DeKalb County | 100,420 | 631.3 | 159 |
| Vermilion County | 74,188 | 898.3 | 83 |
| Williamson County | 67,153 | 420.2 | 160 |
| Adams County | 65,737 | 855.1 | 77 |
| Whiteside County | 55,691 | 684.1 | 81 |
| Boone County | 53,448 | 280.7 | 190 |
| Jackson County | 52,974 | 583.6 | 91 |
| Grundy County | 52,533 | 418.1 | 126 |
| Ogle County | 51,788 | 758.7 | 68 |
| Knox County | 49,967 | 716.4 | 70 |
| Henry County | 49,284 | 823.1 | 60 |
| Coles County | 46,863 | 508.3 | 92 |
| Macoupin County | 44,967 | 863.0 | 52 |
| Stephenson County | 44,630 | 564.2 | 79 |
| Woodford County | 38,467 | 527.6 | 73 |
| Franklin County | 37,804 | 408.9 | 92 |
| Marion County | 37,725 | 572.5 | 66 |
| Jefferson County | 37,113 | 571.2 | 65 |
| Clinton County | 36,903 | 473.9 | 78 |
| Livingston County | 35,815 | 1,043.6 | 34 |
| Monroe County | 34,962 | 385.3 | 91 |
| Effingham County | 34,668 | 478.8 | 72 |
| Lee County | 34,145 | 724.8 | 47 |
| Christian County | 34,032 | 709.5 | 48 |
| Fulton County | 33,609 | 865.7 | 39 |
| Bureau County | 33,244 | 869.1 | 38 |
| Morgan County | 32,915 | 569.0 | 58 |
| Randolph County | 30,163 | 575.4 | 52 |
| Montgomery County | 28,288 | 703.8 | 40 |
| Logan County | 27,987 | 618.1 | 45 |
| McDonough County | 27,238 | 589.3 | 46 |
| Iroquois County | 27,077 | 1,117.4 | 24 |
| Saline County | 23,768 | 380.0 | 63 |
| Jo Daviess County | 22,035 | 600.9 | 37 |
| Jersey County | 21,512 | 369.6 | 58 |
| Fayette County | 21,488 | 716.4 | 30 |
| Shelby County | 20,990 | 758.5 | 28 |
| Perry County | 20,945 | 441.9 | 47 |
| Douglas County | 19,740 | 416.6 | 47 |
| Crawford County | 18,679 | 443.6 | 42 |
| Hancock County | 17,620 | 793.7 | 22 |
| Union County | 17,244 | 413.4 | 42 |
| Edgar County | 16,866 | 623.3 | 27 |
| Warren County | 16,835 | 542.4 | 31 |
| Bond County | 16,725 | 380.3 | 44 |
| Piatt County | 16,673 | 439.2 | 38 |
| Wayne County | 16,179 | 713.8 | 23 |
| Richland County | 15,813 | 360.0 | 44 |
| Carroll County | 15,702 | 445.4 | 35 |
| Mercer County | 15,699 | 561.2 | 28 |
| De Witt County | 15,516 | 397.6 | 39 |
| Clark County | 15,455 | 501.4 | 31 |
| Lawrence County | 15,280 | 372.2 | 41 |
| Pike County | 14,739 | 831.4 | 18 |
| Moultrie County | 14,526 | 336.0 | 43 |
| Massac County | 14,169 | 237.2 | 60 |
| White County | 13,877 | 495.0 | 28 |
| Washington County | 13,761 | 562.6 | 24 |
| Ford County | 13,534 | 485.6 | 28 |
| Johnson County | 13,308 | 343.7 | 39 |
| Clay County | 13,288 | 468.4 | 28 |
| Mason County | 13,086 | 539.4 | 24 |
| Cass County | 13,042 | 375.8 | 35 |
| Menard County | 12,297 | 314.4 | 39 |
| Greene County | 11,985 | 543.1 | 22 |
| Marshall County | 11,742 | 386.8 | 30 |
| Wabash County | 11,361 | 223.3 | 51 |
| Cumberland County | 10,450 | 345.9 | 30 |
| Jasper County | 9,287 | 494.6 | 19 |
| Hamilton County | 7,993 | 434.6 | 18 |
| Schuyler County | 6,902 | 437.3 | 16 |
| Henderson County | 6,387 | 378.8 | 17 |
| Edwards County | 6,245 | 222.4 | 28 |
| Brown County | 6,244 | 305.7 | 20 |
| Putnam County | 5,637 | 160.1 | 35 |
| Stark County | 5,400 | 288.1 | 19 |
| Alexander County | 5,240 | 235.4 | 22 |
| Pulaski County | 5,193 | 199.3 | 26 |
| Scott County | 4,949 | 250.8 | 20 |
| Gallatin County | 4,946 | 322.9 | 15 |
| Calhoun County | 4,437 | 253.8 | 17 |
| Pope County | 3,763 | 368.9 | 10 |
| Hardin County | 3,649 | 177.4 | 21 |
Largest cities in Illinois
| Name | Population | Sq mi | Per sq mi |
|---|---|---|---|
| Chicago, IL | 2,744,467 | 227.7 | 12,050 |
| Aurora, IL | 180,377 | 45.0 | 4,005 |
| Joliet, IL | 150,522 | 65.8 | 2,289 |
| Naperville, IL | 149,639 | 39.1 | 3,826 |
| Rockford, IL | 148,443 | 64.9 | 2,287 |
| Elgin, IL | 114,679 | 38.0 | 3,016 |
| Springfield, IL | 114,392 | 61.2 | 1,870 |
| Peoria, IL | 113,123 | 48.0 | 2,355 |
| Waukegan, IL | 89,405 | 24.2 | 3,692 |
| Champaign, IL | 88,267 | 23.0 | 3,839 |
| Cicero, IL | 85,268 | 5.9 | 14,538 |
| Bloomington, IL | 78,744 | 27.1 | 2,904 |
Showing the 12 most populous of 1,464 — the rest are shown on the map.
Related places
About this page
This page shows demographics for a US state from the 2020 census and the American Community Survey: population, land area, density, and how the state compares to national averages for income, housing, age, and more.
Use the links below to drill into the state's counties and largest cities, or open any point of the state in the radius tool to measure the population within a distance or drive time.