Jamaica is 90 times larger than San Francisco.
Area: 10,991 km2 World Factbook
Population: 2,930,050 (July 2014) World Factbook
Jamaica is an island country situated in the Caribbean Sea, comprising the third-largest island of the Greater Antilles. Wikipedia
Area: 122 km2 calculated
San Francisco, officially the City and County of San Francisco, is the cultural center and a leading financial hub of the San Francisco Bay Area and Northern California. Wikipedia