Manchester, New Hampshire is 21% larger than Waterbury, Connecticut.
Area: 90 km2 calculated
Manchester is the largest city in the U.S. state of New Hampshire, the tenth largest city in New England, and the largest city in northern New England, an area comprising the states of Maine, New Hampshire, and Vermont. It was first named by the merchant and inventor Samuel Blodget. Wikipedia
Area: 75 km2 calculated
Waterbury is a city in the U.S. state of Connecticut on the Naugatuck River, 33 miles southwest of Hartford and 77 miles northeast of New York City. Waterbury is located in New Haven County, Connecticut. Wikipedia