Chicago is 4.7 times larger than Peoria, Illinois.
Area: 608 km2 calculated
Chicago is the third most populous city in the United States, after New York City and Los Angeles. With 2.7 million residents, it is the most populous city in both the U.S. state of Illinois and the American Midwest. Wikipedia
Area: 130 km2 calculated
Peoria is a city in and the county seat of Peoria County, Illinois, United States, and the largest city on the Illinois River. Established in 1691 by the French explorer Henri de Tonti, Peoria is the oldest European settlement in Illinois, and is named after the Peoria tribe. Wikipedia