Kansas City, Kansas is 2.6 times larger than Boston.
Area: 129 km2 calculated
Boston is the capital and largest city of the Commonwealth of Massachusetts in the United States. Boston also serves as county seat of Suffolk County. Wikipedia
Area: 332 km2 calculated
Kansas City is the third-largest city in the state of Kansas, the county seat of Wyandotte County, and the third-largest city of the Kansas City metropolitan area. It is part of a consolidated city-county government known as the "Unified Government". Wikipedia