Toronto is 4.4 times larger than Pittsburgh.
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
Area: 665 km2 calculated
Toronto is the most populous city in Canada and the provincial capital of Ontario. It is located in Southern Ontario on the northwestern shore of Lake Ontario. The history of Toronto began in the late 18th century when the British Crown purchased its land from the Mississaugas of the New Credit. Wikipedia