The map above shows Illinois and Western Australia side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Illinois vs Western Australia Geography
Land area: Illinois has a land area of 55,513 square miles (143,778 km²), while Western Australia has 975,685 square miles (2,527,013 km²). Western Australia's land area is 17.6 times larger than Illinois'.
Total area: Illinois: 57,913 square miles (149,995 km²) vs Western Australia: 975,685 square miles (2,527,013 km²), including inland and coastal water. Western Australia's total area is 16.8 times larger than Illinois'.
Length: Illinois is 390 miles (628 km) long from north to south; Western Australia is 1,590 miles (2,558 km). Western Australia's north-south length is 4.1 times (308%) longer than Illinois'.
Width: Illinois spans 283 miles (456 km) east to west; Western Australia spans 1,286 miles (2,069 km). Western Australia's east-west width is 4.5 times (354%) wider than Illinois'.
Highest point: Illinois's highest point is Charles Mound at 1,232 feet (376 m); Western Australia's is Mount Meharry at 4,098 feet (1,249 m). Mount Meharry is 2,866 feet higher than Charles Mound.
Lowest point: Illinois's lowest point is Mississippi River at 292 feet; Western Australia's is Indian Ocean at 0 feet. Western Australia's lowest point is 292 feet lower.
Illinois vs Western Australia Population and History
Population: Illinois has a population of 12,710,158 (2024), while Western Australia has 3,061,672 (2025). Illinois' population is 4.2 times (315%) larger than Western Australia's.
Population density: Illinois: 229.0 people per square mile vs Western Australia: 3.1. Illinois' population density is 73.9 times higher than Western Australia's.
Largest metro area: Illinois's largest metropolitan area is Chicago-Naperville-Elgin, IL-IN metro area (9,408,576 people) vs Western Australia's Greater Perth (2,452,765). Chicago-Naperville-Elgin, IL-IN metro area's population is 3.8 times (284%) larger than Greater Perth's.
History: Illinois: Admitted to the Union on December 3, 1818, as the 21st state. Western Australia: Became an Australian state at Federation on January 1, 1901; founded as a colony in 1829. In its current form, Illinois is the older of the two by 83 years.
Illinois vs Western Australia Economy
GDP: Illinois's GDP is $1,148.1 billion (2024) vs Western Australia's $304.6 billion. Illinois' economic output is 3.8 times (277%) larger than Western Australia's.
GDP per capita: Illinois: $90,330 per person vs Western Australia: $99,488. Western Australia's GDP per capita is 1.1 times (10%) higher than Illinois'.
Official Websites
Illinois official website · Western Australia official website
More Size Comparisons
All Illinois size comparisons · All Western Australia 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.