The map above shows Delaware and Illinois side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Delaware vs Illinois Geography
Land area: Delaware has a land area of 1,949 square miles (5,047 km²), while Illinois has 55,513 square miles (143,778 km²). Illinois' land area is 28.5 times larger than Delaware's.
Total area: Delaware: 2,489 square miles (6,446 km²) vs Illinois: 57,913 square miles (149,995 km²), including inland and coastal water. Illinois' total area is 23.3 times larger than Delaware's.
Length: Delaware is 98 miles (158 km) long from north to south; Illinois is 390 miles (628 km). Illinois' north-south length is 4.0 times (298%) longer than Delaware's.
Width: Delaware spans 96 miles (155 km) east to west; Illinois spans 283 miles (456 km). Illinois' east-west width is 2.9 times (195%) wider than Delaware's.
Highest point: Delaware's highest point is Ebright Azimuth at 450 feet (137 m); Illinois's is Charles Mound at 1,232 feet (376 m). Charles Mound is 782 feet higher than Ebright Azimuth.
Lowest point: Delaware's lowest point is Atlantic Ocean at 0 feet; Illinois's is Mississippi River at 292 feet. Delaware's lowest point is 292 feet lower.
Delaware vs Illinois Population and History
Population: Delaware has a population of 1,051,917 (2024), while Illinois has 12,710,158 (2024). Illinois' population is 12.1 times larger than Delaware's.
Population density: Delaware: 539.9 people per square mile vs Illinois: 229.0. Delaware's population density is 2.4 times (136%) higher than Illinois'.
Biggest city: Delaware's biggest city is Wilmington with 73,176 people; Illinois's is Chicago with 2,721,308. Chicago's population is 37.2 times larger than Wilmington's.
Largest metro area: Delaware's largest metropolitan area is Philadelphia-Camden-Wilmington, PA-NJ-DE-MD metro area (6,330,422 people) vs Illinois's Chicago-Naperville-Elgin, IL-IN metro area (9,408,576). Chicago-Naperville-Elgin, IL-IN metro area's population is 1.5 times (49%) larger than Philadelphia-Camden-Wilmington, PA-NJ-DE-MD metro area's.
History: Delaware: Admitted to the Union on December 7, 1787, as the 1st state. Illinois: Admitted to the Union on December 3, 1818, as the 21st state. In its current form, Delaware is the older of the two by 31 years.
Delaware vs Illinois Economy
GDP: Delaware's GDP is $111.0 billion (2024) vs Illinois's $1,148.1 billion. Illinois' economic output is 10.3 times larger than Delaware's.
GDP per capita: Delaware: $105,495 per person vs Illinois: $90,330. Delaware's GDP per capita is 1.2 times (17%) higher than Illinois'.
Average income: Delaware: $68,061 vs Illinois: $74,522 average income per person (per capita personal income). Illinois' average income is 1.1 times (9%) higher than Delaware's.
Delaware vs Illinois Counties
Number of counties: Delaware has 3 counties, while Illinois has 102. Illinois' county count is 34.0 times higher than Delaware's.
Biggest county by area: Delaware's largest county is Sussex County at 936 square miles; Illinois's is McLean County at 1,183 square miles. McLean County's land area is 1.3 times (26%) larger than Sussex County's.
Smallest county by area: Delaware: New Castle County (426 sq mi) vs Illinois: Putnam County (160 sq mi). New Castle County's land area is 2.7 times (166%) larger than Putnam County's.
Most populous county: Delaware: New Castle County (588,093 people) vs Illinois: Cook County (5,182,617 people). Cook County's population is 8.8 times (781%) larger than New Castle County's.
Least populous county: Delaware: Kent County (192,690 people) vs Illinois: Hardin County (3,550 people). Kent County's population is 54.3 times larger than Hardin County's.
Richest county: Delaware: Sussex County ($73,647 per capita income) vs Illinois: Cumberland County ($104,890). Cumberland County's income is 1.4 times (42%) richer than Sussex County's.
Poorest county: Delaware: Kent County ($55,474 per capita income) vs Illinois: Lawrence County ($43,606). Kent County's income is 1.3 times (27%) richer than Lawrence County's.
Delaware vs Illinois Taxes
State income tax: Delaware has a top income tax rate of 6.6%, while Illinois has a top income tax rate of 4.95%. Delaware's top rate is 1.65 percentage points higher.
Property tax: Delaware: 0.47% effective rate vs Illinois: 1.92% of home value per year. Illinois's rate is 1.45 percentage points higher.
Sales tax: Delaware: 0% combined state and average local rate vs Illinois: 8.98%. Illinois's combined rate is 8.98 percentage points higher.
Official Websites
Delaware official website · Illinois official website
More Size Comparisons
All Delaware size comparisons · All Illinois 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.