Philadelphia is 47% larger than Milwaukee.
Area: 251 km2 calculated
Milwaukee is the largest city in the U.S. state of Wisconsin, the 30th most populous city in the United States, and 39th most populous region in the United States. It is the county seat of Milwaukee County and is located on the southwestern shore of Lake Michigan. Wikipedia
Area: 370 km2 calculated
Philadelphia is the largest city in the Commonwealth of Pennsylvania, the fifth-most-populous city in the United States, and the core of the sixth-largest metropolitan area in the country. Wikipedia