Chicago is 16 times larger than Jersey City, New Jersey.
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: 38 km2 calculated
Jersey City is the seat of Hudson County, New Jersey. As of the 2010 United States Census, the population of Jersey City was 247,597, making it the second-most populous city in New Jersey, after Newark. Wikipedia