Boston is 3.1 times larger than West Covina, California.
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: 42 km2 calculated
West Covina is a city in Los Angeles County, California, located 19 miles east of Downtown Los Angeles in the eastern San Gabriel Valley and is part of Greater Los Angeles. The population for the city was 106,098 at the 2010 census. Wikipedia