The map above shows Illinois and New Jersey side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Illinois vs New Jersey Geography
Land area
- Illinois has a land area of 55,513 square miles (143,778 km²), while New Jersey has 7,355 square miles (19,049 km²).
- Illinois' land area is 7.5 times (655%) larger than New Jersey's.
Total area
- Illinois: 57,913 square miles (149,995 km²) vs New Jersey: 8,719 square miles (22,583 km²), including inland and coastal water.
- Illinois' total area is 6.6 times (564%) larger than New Jersey's.
Length
- Illinois is 390 miles (628 km) long from north to south; New Jersey is 169 miles (271 km).
- Illinois' north-south length is 2.3 times (131%) longer than New Jersey's.
Width
- Illinois spans 283 miles (456 km) east to west; New Jersey spans 129 miles (207 km).
- Illinois' east-west width is 2.2 times (119%) wider than New Jersey's.
Highest point
- Illinois's highest point is Charles Mound at 1,232 feet (376 m); New Jersey's is High Point at 1,798 feet (548 m).
- High Point is 566 feet higher than Charles Mound.
Lowest point
- Illinois's lowest point is Mississippi River at 292 feet; New Jersey's is Atlantic Ocean at 0 feet.
- New Jersey's lowest point is 292 feet lower.
Illinois vs New Jersey Population and History
Population
- Illinois has a population of 12,710,158 (2024), while New Jersey has 9,500,851 (2024).
- Illinois' population is 1.3 times (34%) larger than New Jersey's.
Population density
- Illinois: 229.0 people per square mile vs New Jersey: 1,291.8.
- New Jersey's population density is 5.6 times (464%) higher than Illinois'.
Biggest city
- Illinois's biggest city is Chicago with 2,721,308 people; New Jersey's is Newark with 317,303.
- Chicago's population is 8.6 times (758%) larger than Newark's.
Largest metro area
- Illinois's largest metropolitan area is Chicago-Naperville-Elgin, IL-IN metro area (9,408,576 people) vs New Jersey's New York-Newark-Jersey City, NY-NJ metro area (19,940,274).
- New York-Newark-Jersey City, NY-NJ metro area's population is 2.1 times (112%) larger than Chicago-Naperville-Elgin, IL-IN metro area's.
History
- Illinois: Admitted to the Union on December 3, 1818, as the 21st state.
- New Jersey: Admitted to the Union on December 18, 1787, as the 3rd state.
- In its current form, New Jersey is the older of the two by 31 years.
Illinois vs New Jersey Economy
GDP
- Illinois's GDP is $1,148.1 billion (2024) vs New Jersey's $846.0 billion.
- Illinois' economic output is 1.4 times (36%) larger than New Jersey's.
GDP per capita
- Illinois: $90,330 per person vs New Jersey: $89,045.
- Illinois and New Jersey have about the same GDP per capita.
Average income
- Illinois: $74,522 vs New Jersey: $84,893 average income per person (per capita personal income).
- New Jersey's average income is 1.1 times (14%) higher than Illinois'.
Illinois vs New Jersey Counties
Number of counties
- Illinois has 102 counties, while New Jersey has 21.
- Illinois' county count is 4.9 times (386%) higher than New Jersey's.
Biggest county by area
- Illinois's largest county is McLean County at 1,183 square miles; New Jersey's is Burlington County at 799 square miles.
- McLean County's land area is 1.5 times (48%) larger than Burlington County's.
Smallest county by area
- Illinois: Putnam County (160 sq mi) vs New Jersey: Hudson County (46 sq mi).
- Putnam County's land area is 3.5 times (247%) larger than Hudson County's.
Most populous county
- Illinois: Cook County (5,182,617 people) vs New Jersey: Bergen County (978,641 people).
- Cook County's population is 5.3 times (430%) larger than Bergen County's.
Least populous county
- Illinois: Hardin County (3,550 people) vs New Jersey: Salem County (65,874 people).
- Salem County's population is 18.6 times larger than Hardin County's.
Richest county
- Illinois: Cumberland County ($104,890 per capita income) vs New Jersey: Somerset County ($121,042).
- Somerset County's income is 1.2 times (15%) richer than Cumberland County's.
Poorest county
- Illinois: Lawrence County ($43,606 per capita income) vs New Jersey: Cumberland County ($50,843).
- Cumberland County's income is 1.2 times (17%) richer than Lawrence County's.
Illinois vs New Jersey Taxes
State income tax
- Illinois has a top income tax rate of 4.95%, while New Jersey has a top income tax rate of 10.75%.
- New Jersey's top rate is 5.8 percentage points higher.
Property tax
- Illinois: 1.92% effective rate vs New Jersey: 1.89% of home value per year.
- Illinois's rate is 0.03 percentage points higher.
Sales tax
- Illinois: 8.98% combined state and average local rate vs New Jersey: 6.6%.
- Illinois's combined rate is 2.38 percentage points higher.
Official Websites
Illinois official website · New Jersey official website
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More Size Comparisons
All Illinois size comparisons · All New Jersey 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.