The map above shows Illinois and Iowa side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Illinois vs Iowa Geography
Land area: Illinois has a land area of 55,513 square miles (143,778 km²), while Iowa has 55,854 square miles (144,660 km²). Illinois and Iowa have about the same land area.
Total area: Illinois: 57,913 square miles (149,995 km²) vs Iowa: 56,273 square miles (145,746 km²), including inland and coastal water. Illinois and Iowa have about the same total area.
Length: Illinois is 390 miles (628 km) long from north to south; Iowa is 216 miles (347 km). Illinois' north-south length is 1.8 times (81%) longer than Iowa's.
Width: Illinois spans 283 miles (456 km) east to west; Iowa spans 335 miles (539 km). Iowa's east-west width is 1.2 times (18%) wider than Illinois'.
Highest point: Illinois's highest point is Charles Mound at 1,232 feet (376 m); Iowa's is Hawkeye Point at 1,669 feet (509 m). Hawkeye Point is 437 feet higher than Charles Mound.
Lowest point: Illinois's lowest point is Mississippi River at 292 feet; Iowa's is Mississippi River at 480 feet. Illinois's lowest point is 188 feet lower.
Illinois vs Iowa Population and History
Population: Illinois has a population of 12,710,158 (2024), while Iowa has 3,241,488 (2024). Illinois' population is 3.9 times (292%) larger than Iowa's.
Population density: Illinois: 229.0 people per square mile vs Iowa: 58.0. Illinois' population density is 3.9 times (295%) higher than Iowa's.
Biggest city: Illinois's biggest city is Chicago with 2,721,308 people; Iowa's is Des Moines with 213,096. Chicago's population is 12.8 times larger than Des Moines'.
Largest metro area: Illinois's largest metropolitan area is Chicago-Naperville-Elgin, IL-IN metro area (9,408,576 people) vs Iowa's Omaha, NE-IA metro area (1,001,010). Chicago-Naperville-Elgin, IL-IN metro area's population is 9.4 times (840%) larger than Omaha, NE-IA metro area's.
History: Illinois: Admitted to the Union on December 3, 1818, as the 21st state. Iowa: Admitted to the Union on December 28, 1846, as the 29th state. In its current form, Illinois is the older of the two by 28 years.
Illinois vs Iowa Economy
GDP: Illinois's GDP is $1,148.1 billion (2024) vs Iowa's $265.8 billion. Illinois' economic output is 4.3 times (332%) larger than Iowa's.
GDP per capita: Illinois: $90,330 per person vs Iowa: $81,998. Illinois' GDP per capita is 1.1 times (10%) higher than Iowa's.
Average income: Illinois: $74,522 vs Iowa: $65,225 average income per person (per capita personal income). Illinois' average income is 1.1 times (14%) higher than Iowa's.
Illinois vs Iowa Counties
Number of counties: Illinois has 102 counties, while Iowa has 99. Illinois and Iowa have about the same county count.
Biggest county by area: Illinois's largest county is McLean County at 1,183 square miles; Iowa's is Kossuth County at 973 square miles. McLean County's land area is 1.2 times (22%) larger than Kossuth County's.
Smallest county by area: Illinois: Putnam County (160 sq mi) vs Iowa: Dickinson County (381 sq mi). Dickinson County's land area is 2.4 times (138%) larger than Putnam County's.
Most populous county: Illinois: Cook County (5,182,617 people) vs Iowa: Polk County (516,185 people). Cook County's population is 10.0 times larger than Polk County's.
Least populous county: Illinois: Hardin County (3,550 people) vs Iowa: Adams County (3,606 people). Hardin County and Adams County have about the same population.
Richest county: Illinois: Cumberland County ($104,890 per capita income) vs Iowa: Mitchell County ($98,211). Cumberland County's income is 1.1 times (7%) richer than Mitchell County's.
Poorest county: Illinois: Lawrence County ($43,606 per capita income) vs Iowa: Decatur County ($46,134). Decatur County's income is 1.1 times (6%) richer than Lawrence County's.
Illinois vs Iowa Taxes
State income tax: Illinois has a top income tax rate of 4.95%, while Iowa has a top income tax rate of 3.8%. Illinois's top rate is 1.15 percentage points higher.
Property tax: Illinois: 1.92% effective rate vs Iowa: 1.29% of home value per year. Illinois's rate is 0.63 percentage points higher.
Sales tax: Illinois: 8.98% combined state and average local rate vs Iowa: 6.94%. Illinois's combined rate is 2.04 percentage points higher.
Official Websites
Illinois official website · Iowa official website
More Size Comparisons
All Illinois size comparisons · All Iowa size comparisons
Area, elevation and boundary figures come from official national statistics and US Census Bureau and Natural Earth boundary data; US state population, economic, county and tax figures come from the US Census Bureau, the Bureau of Economic Analysis and the Tax Foundation. Figures are rounded and for general reference.