The map above shows Illinois and Northern Territory side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Illinois vs Northern Territory Geography
Land area: Illinois has a land area of 55,513 square miles (143,778 km²), while Northern Territory has 520,902 square miles (1,349,129 km²). Northern Territory's land area is 9.4 times (838%) larger than Illinois'.
Total area: Illinois: 57,913 square miles (149,995 km²) vs Northern Territory: 520,902 square miles (1,349,129 km²), including inland and coastal water. Northern Territory's total area is 9.0 times (799%) larger than Illinois'.
Length: Illinois is 390 miles (628 km) long from north to south; Northern Territory is 1,092 miles (1,758 km). Northern Territory's north-south length is 2.8 times (180%) longer than Illinois'.
Width: Illinois spans 283 miles (456 km) east to west; Northern Territory spans 610 miles (981 km). Northern Territory's east-west width is 2.2 times (116%) wider than Illinois'.
Highest point: Illinois's highest point is Charles Mound at 1,232 feet (376 m); Northern Territory's is Mount Zeil at 5,023 feet (1,531 m). Mount Zeil is 3,791 feet higher than Charles Mound.
Lowest point: Illinois's lowest point is Mississippi River at 292 feet; Northern Territory's is Timor Sea at 0 feet. Northern Territory's lowest point is 292 feet lower.
Illinois vs Northern Territory Population and History
Population: Illinois has a population of 12,710,158 (2024), while Northern Territory has 265,457 (2025). Illinois' population is 47.9 times larger than Northern Territory's.
Population density: Illinois: 229.0 people per square mile vs Northern Territory: 0.5. Illinois' population density is 458.0 times higher than Northern Territory's.
Largest metro area: Illinois's largest metropolitan area is Chicago-Naperville-Elgin, IL-IN metro area (9,408,576 people) vs Northern Territory's Greater Darwin (159,284). Chicago-Naperville-Elgin, IL-IN metro area's population is 59.1 times larger than Greater Darwin's.
History: Illinois: Admitted to the Union on December 3, 1818, as the 21st state. Northern Territory: Became a federal territory on January 1, 1911; self-governing since 1978. In its current form, Illinois is the older of the two by 93 years.
Illinois vs Northern Territory Economy
GDP: Illinois's GDP is $1,148.1 billion (2024) vs Northern Territory's $22.4 billion. Illinois' economic output is 51.3 times larger than Northern Territory's.
GDP per capita: Illinois: $90,330 per person vs Northern Territory: $84,383. Illinois' GDP per capita is 1.1 times (7%) higher than Northern Territory's.
Official Websites
Illinois official website · Northern Territory official website
More Size Comparisons
All Illinois size comparisons · All Northern Territory 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.