Bordering states
Illinois vs Iowa
Short answer
- IL
- 12,710,158
- IA
- 3,241,488
The two states, county by county
Both maps share one density scale, so the same shade means the same number of people per square mile on either side of the border. Darker counties are denser. Select a county to open its page.
Illinois
Iowa
- < 20
- < 28
- < 43
- < 83
- ≥ 83
Side by side
| Measure | Illinois | Iowa |
|---|---|---|
| Residents, 2024 | 12,710,158 | 3,241,488 |
| Rank by population | 6th | 32nd |
| Land, sq mi | 55,513 | 55,854 |
| People per sq mi | 229.0 | 58.0 |
| County-equivalents | 102 | 99 |
| Median county residents | 24,447 | 15,008 |
| Median county income | $65,901 | $68,654 |
| Most populous county | Cook County | Polk County |
| Largest county by land | McLean County | Kossuth County |
| Capital | Springfield | Des Moines |
| Daylight at capital, June 21 | 15 h 00 min | 15 h 12 min |
| Census division | East North Central | West North Central |
Population and density
Illinois has 12,710,158 residents, 3.9 times Iowa's 3,241,488. Illinois ranks 6th and Iowa 32nd of the 50 states and DC. Illinois is the more crowded, with 229.0 people per square mile against 58.0, 3.9 times.
Land area
Iowa has 55,854 square miles of land, about the same as Illinois's 55,513. The largest county-equivalent in Illinois is McLean County at 1,183 square miles; in Iowa it is Kossuth County at 973.
Counties
Illinois is divided into 102 county-equivalents and Iowa into 99, so an average Illinois county covers 544 square miles against 564. The typical county in Illinois has 24,447 residents, against 15,008 in Iowa. The most populous are Cook County (5,182,617) and Polk County (516,185).
33 county names appear on both sides of the border: Adams, Boone, Calhoun, Carroll, Cass, Clay, Clinton, Crawford, Fayette, Franklin, Greene, Grundy, Hamilton, Hancock, Hardin, Henry, Jackson, Jasper, Jefferson, Johnson, Lee, Madison, Marion, Marshall, Monroe, Montgomery, Scott, Shelby, Union, Warren, Washington, Wayne, Winnebago. Use the FIPS code, not the name, when joining data across the two states.
Household income
The median county in Iowa has a household income of $68,654, 4% above Illinois's $65,901. The highest county incomes are Kendall County ($114,606) in Illinois and Dallas County ($102,189) in Iowa, from SAIPE 2023.
Capitals and daylight
Springfield and Des Moines are 242 miles apart in a straight line; from Springfield the initial bearing is 302°, WNW. On June 21, 2026, Springfield gets 15 h 00 min of daylight and Des Moines 15 h 12 min; on December 21 the figures are 9 h 21 min and 9 h 10 min. Month by month tables are on the Springfield and Des Moines daylight pages.
Where they sit
Both are in the Midwest region, but Illinois is in the East North Central division and Iowa in the West North Central division. By county internal points, Illinois spans 2 UTM zones and Iowa 2.
Questions people ask
Which is bigger, Illinois or Iowa?
Iowa, with 55,854 square miles of land against 55,513, 1.01 times as large.
Which has more people, Illinois or Iowa?
Illinois has 12,710,158 residents, 3.9 times Iowa's 3,241,488.
How far is Springfield from Des Moines?
242 miles in a straight line, heading WNW (302°) from Springfield.
Do Illinois and Iowa have counties with the same name?
Yes, 33: Adams, Boone, Calhoun, Carroll, Cass, Clay, Clinton, Crawford, Fayette, Franklin, Greene, Grundy, Hamilton, Hancock, Hardin, Henry, Jackson, Jasper, Jefferson, Johnson, Lee, Madison, Marion, Marshall, Monroe, Montgomery, Scott, Shelby, Union, Warren, Washington, Wayne, Winnebago.
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.
- 01Census Vintage 2024 county population estimates
- 02Census 2024 Gazetteer, counties
- 03Census SAIPE 2023 state and county estimates
- 04Census Bureau regions and divisions of the United States (last verified 2026-09-30)
How every number is computed: methodology. Spotted a wrong figure? Report an error.