Maine (USA) is 5.8 times larger than Puerto Rico.
Area: 13,790 km2 World Factbook
Population: 3,620,897 (July 2014) World Factbook
Puerto Rico, officially the Commonwealth of Puerto Rico, is an unincorporated territory of the United States, located in the northeastern Caribbean east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands. Wikipedia
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south; New Hampshire to the west; and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Wikipedia