The map above shows Arizona and Illinois side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Arizona vs Illinois Geography
Land area: Arizona has a land area of 113,655 square miles (294,366 km²), while Illinois has 55,513 square miles (143,778 km²). Arizona's land area is 2.0 times (105%) larger than Illinois'.
Total area: Arizona: 113,985 square miles (295,220 km²) vs Illinois: 57,913 square miles (149,995 km²), including inland and coastal water. Arizona's total area is 2.0 times (97%) larger than Illinois'.
Length: Arizona is 429 miles (690 km) long from north to south; Illinois is 390 miles (628 km). Arizona's north-south length is 1.1 times (10%) longer than Illinois'.
Width: Arizona spans 452 miles (727 km) east to west; Illinois spans 283 miles (456 km). Arizona's east-west width is 1.6 times (60%) wider than Illinois'.
Highest point: Arizona's highest point is Humphreys Peak at 12,620 feet (3,847 m); Illinois's is Charles Mound at 1,232 feet (376 m). Humphreys Peak is 11,388 feet higher than Charles Mound.
Lowest point: Arizona's lowest point is Colorado River at 71 feet; Illinois's is Mississippi River at 292 feet. Arizona's lowest point is 221 feet lower.
Arizona vs Illinois Population and History
Population: Arizona has a population of 7,582,384 (2024), while Illinois has 12,710,158 (2024). Illinois' population is 1.7 times (68%) larger than Arizona's.
Population density: Arizona: 66.7 people per square mile vs Illinois: 229.0. Illinois' population density is 3.4 times (243%) higher than Arizona's.
Biggest city: Arizona's biggest city is Phoenix with 1,673,164 people; Illinois's is Chicago with 2,721,308. Chicago's population is 1.6 times (63%) larger than Phoenix's.
Largest metro area: Arizona's largest metropolitan area is Phoenix-Mesa-Chandler, AZ metro area (5,186,958 people) vs Illinois's Chicago-Naperville-Elgin, IL-IN metro area (9,408,576). Chicago-Naperville-Elgin, IL-IN metro area's population is 1.8 times (81%) larger than Phoenix-Mesa-Chandler, AZ metro area's.
History: Arizona: Admitted to the Union on February 14, 1912, as the 48th state. Illinois: Admitted to the Union on December 3, 1818, as the 21st state. In its current form, Illinois is the older of the two by 94 years.
Arizona vs Illinois Economy
GDP: Arizona's GDP is $570.1 billion (2024) vs Illinois's $1,148.1 billion. Illinois' economic output is 2.0 times (101%) larger than Arizona's.
GDP per capita: Arizona: $75,186 per person vs Illinois: $90,330. Illinois' GDP per capita is 1.2 times (20%) higher than Arizona's.
Average income: Arizona: $65,798 vs Illinois: $74,522 average income per person (per capita personal income). Illinois' average income is 1.1 times (13%) higher than Arizona's.
Arizona vs Illinois Counties
Number of counties: Arizona has 15 counties, while Illinois has 102. Illinois' county count is 6.8 times (580%) higher than Arizona's.
Biggest county by area: Arizona's largest county is Coconino County at 18,616 square miles; Illinois's is McLean County at 1,183 square miles. Coconino County's land area is 15.7 times larger than McLean County's.
Smallest county by area: Arizona: Santa Cruz County (1,236 sq mi) vs Illinois: Putnam County (160 sq mi). Santa Cruz County's land area is 7.7 times (672%) larger than Putnam County's.
Most populous county: Arizona: Maricopa County (4,673,096 people) vs Illinois: Cook County (5,182,617 people). Cook County's population is 1.1 times (11%) larger than Maricopa County's.
Least populous county: Arizona: Greenlee County (9,410 people) vs Illinois: Hardin County (3,550 people). Greenlee County's population is 2.7 times (165%) larger than Hardin County's.
Richest county: Arizona: Maricopa County ($72,176 per capita income) vs Illinois: Cumberland County ($104,890). Cumberland County's income is 1.5 times (45%) richer than Maricopa County's.
Poorest county: Arizona: Graham County ($44,164 per capita income) vs Illinois: Lawrence County ($43,606). Graham County and Lawrence County have about the same income.
Arizona vs Illinois Taxes
State income tax: Arizona has a top income tax rate of 2.5%, while Illinois has a top income tax rate of 4.95%. Illinois's top rate is 2.45 percentage points higher.
Property tax: Arizona: 0.43% effective rate vs Illinois: 1.92% of home value per year. Illinois's rate is 1.49 percentage points higher.
Sales tax: Arizona: 8.54% combined state and average local rate vs Illinois: 8.98%. Illinois's combined rate is 0.44 percentage points higher.
Official Websites
Arizona official website · Illinois official website
More Size Comparisons
All Arizona 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.