The map above shows Illinois and Maryland side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Illinois vs Maryland Geography
Land area: Illinois has a land area of 55,513 square miles (143,778 km²), while Maryland has 9,711 square miles (25,151 km²). Illinois' land area is 5.7 times (472%) larger than Maryland's.
Total area: Illinois: 57,913 square miles (149,995 km²) vs Maryland: 12,406 square miles (32,131 km²), including inland and coastal water. Illinois' total area is 4.7 times (367%) larger than Maryland's.
Length: Illinois is 390 miles (628 km) long from north to south; Maryland is 231 miles (371 km). Illinois' north-south length is 1.7 times (69%) longer than Maryland's.
Width: Illinois spans 283 miles (456 km) east to west; Maryland spans 243 miles (391 km). Illinois' east-west width is 1.2 times (16%) wider than Maryland's.
Highest point: Illinois's highest point is Charles Mound at 1,232 feet (376 m); Maryland's is Hoye-Crest at 3,362 feet (1,025 m). Hoye-Crest is 2,130 feet higher than Charles Mound.
Lowest point: Illinois's lowest point is Mississippi River at 292 feet; Maryland's is Atlantic Ocean at 0 feet. Maryland's lowest point is 292 feet lower.
Illinois vs Maryland Population and History
Population: Illinois has a population of 12,710,158 (2024), while Maryland has 6,263,220 (2024). Illinois' population is 2.0 times (103%) larger than Maryland's.
Population density: Illinois: 229.0 people per square mile vs Maryland: 645.0. Maryland's population density is 2.8 times (182%) higher than Illinois'.
Biggest city: Illinois's biggest city is Chicago with 2,721,308 people; Maryland's is Baltimore with 568,271. Chicago's population is 4.8 times (379%) larger than Baltimore's.
Largest metro area: Illinois's largest metropolitan area is Chicago-Naperville-Elgin, IL-IN metro area (9,408,576 people) vs Maryland's Washington-Arlington-Alexandria, DC-VA-MD-WV metro area (6,436,489). Chicago-Naperville-Elgin, IL-IN metro area's population is 1.5 times (46%) larger than Washington-Arlington-Alexandria, DC-VA-MD-WV metro area's.
History: Illinois: Admitted to the Union on December 3, 1818, as the 21st state. Maryland: Admitted to the Union on April 28, 1788, as the 7th state. In its current form, Maryland is the older of the two by 30 years.
Illinois vs Maryland Economy
GDP: Illinois's GDP is $1,148.1 billion (2024) vs Maryland's $546.0 billion. Illinois' economic output is 2.1 times (110%) larger than Maryland's.
GDP per capita: Illinois: $90,330 per person vs Maryland: $87,180. Illinois and Maryland have about the same GDP per capita.
Average income: Illinois: $74,522 vs Maryland: $79,259 average income per person (per capita personal income). Maryland's average income is 1.1 times (6%) higher than Illinois'.
Illinois vs Maryland Counties
Number of counties: Illinois has 102 counties, while Maryland has 24. Illinois' county count is 4.3 times (325%) higher than Maryland's.
Biggest county by area: Illinois's largest county is McLean County at 1,183 square miles; Maryland's is Frederick County at 661 square miles. McLean County's land area is 1.8 times (79%) larger than Frederick County's.
Smallest county by area: Illinois: Putnam County (160 sq mi) vs Maryland: Baltimore city (81 sq mi). Putnam County's land area is 2.0 times (98%) larger than Baltimore city's.
Most populous county: Illinois: Cook County (5,182,617 people) vs Maryland: Montgomery County (1,082,273 people). Cook County's population is 4.8 times (379%) larger than Montgomery County's.
Least populous county: Illinois: Hardin County (3,550 people) vs Maryland: Kent County (19,557 people). Kent County's population is 5.5 times (451%) larger than Hardin County's.
Richest county: Illinois: Cumberland County ($104,890 per capita income) vs Maryland: Montgomery County ($104,882). Cumberland County and Montgomery County have about the same income.
Poorest county: Illinois: Lawrence County ($43,606 per capita income) vs Maryland: Somerset County ($41,421). Lawrence County's income is 1.1 times (5%) richer than Somerset County's.
Illinois vs Maryland Taxes
State income tax: Illinois has a top income tax rate of 4.95%, while Maryland has a top income tax rate of 6.5%. Maryland's top rate is 1.55 percentage points higher.
Property tax: Illinois: 1.92% effective rate vs Maryland: 0.95% of home value per year. Illinois's rate is 0.97 percentage points higher.
Sales tax: Illinois: 8.98% combined state and average local rate vs Maryland: 6%. Illinois's combined rate is 2.98 percentage points higher.
Official Websites
Illinois official website · Maryland official website
More Size Comparisons
All Illinois size comparisons · All Maryland 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.