Columbus, Ohio is 4.5 times larger than Pittsburgh.
Area: 694 km2 calculated
Columbus is the capital of and the largest city in the U.S. state of Ohio. It is the 15th largest city in the United States with a population of 822,553. It is the core city of the Columbus, OH Metropolitan Statistical Area, which encompasses a ten county area. Wikipedia
Area: 153 km2 calculated
Pittsburgh is the seat of Allegheny County and with a population of 305,841 is the second-largest city in the U.S. state of Pennsylvania. With a metropolitan CSA population of 2,659,937, it is the largest in both the Ohio Valley and Appalachia and the 20th-largest in the U.S. Wikipedia