The map above shows Illinois and Northern Ireland side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Illinois vs Northern Ireland Geography
Land area: Illinois has a land area of 55,513 square miles (143,778 km²), while Northern Ireland has 5,236 square miles (13,562 km²). Illinois' land area is 10.6 times larger than Northern Ireland's.
Total area: Illinois: 57,913 square miles (149,995 km²) vs Northern Ireland: 5,456 square miles (14,130 km²), including inland and coastal water. Illinois' total area is 10.6 times larger than Northern Ireland's.
Length: Illinois is 390 miles (628 km) long from north to south; Northern Ireland is 83 miles (134 km). Illinois' north-south length is 4.7 times (370%) longer than Northern Ireland's.
Width: Illinois spans 283 miles (456 km) east to west; Northern Ireland spans 107 miles (173 km). Illinois' east-west width is 2.6 times (164%) wider than Northern Ireland's.
Highest point: Illinois's highest point is Charles Mound at 1,232 feet (376 m); Northern Ireland's is Slieve Donard at 2,789 feet (850 m). Slieve Donard is 1,557 feet higher than Charles Mound.
Lowest point: Illinois's lowest point is Mississippi River at 292 feet; Northern Ireland's is Irish Sea at 0 feet. Northern Ireland's lowest point is 292 feet lower.
Illinois vs Northern Ireland Population and History
Population: Illinois has a population of 12,710,158 (2024), while Northern Ireland has 1,905,000 (2022). Illinois' population is 6.7 times (567%) larger than Northern Ireland's.
Population density: Illinois: 229.0 people per square mile vs Northern Ireland: 363.8. Northern Ireland's population density is 1.6 times (59%) higher than Illinois'.
Biggest city: Illinois's biggest city is Chicago with 2,721,308 people; Northern Ireland's is Belfast with 348,005. Chicago's population is 7.8 times (682%) larger than Belfast's.
History: Illinois: Admitted to the Union on December 3, 1818, as the 21st state. Northern Ireland: A country within the United Kingdom; created by the partition of Ireland on May 3, 1921. In its current form, Illinois is the older of the two by 103 years.
Illinois vs Northern Ireland Economy
GDP: Illinois's GDP is $1,148.1 billion (2024) vs Northern Ireland's $58.8 billion. Illinois' economic output is 19.5 times larger than Northern Ireland's.
GDP per capita: Illinois: $90,330 per person vs Northern Ireland: $30,686. Illinois' GDP per capita is 2.9 times (194%) higher than Northern Ireland's.
Official Websites
Illinois official website · Northern Ireland official website
More Size Comparisons
All Illinois size comparisons · All Northern Ireland 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.