Chicago is 30% larger than Andorra.
Area: 468 km2 World Factbook
Population: 85,458 (July 2014) World Factbook
Andorra, officially the Principality of Andorra, also called the Principality of the Valleys of Andorra, is a landlocked microstate in Southwestern Europe, located in the eastern Pyrenees mountains and bordered by Spain and France. Wikipedia
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