Puerto Rico is 25 times larger than Guam.
Area: 544 km2 World Factbook
Population: 161,001 (July 2014) World Factbook
Guam is an organized, unincorporated territory of the United States in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Wikipedia
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