Singapore is 5.7 times larger than San Francisco.
Area: 697 km2 World Factbook
Population: 5,567,301 (July 2014) World Factbook
Singapore, officially the Republic of Singapore, is a sovereign city-state and island country in Southeast Asia. It lies off the southern tip of the Malay Peninsula and is 137 kilometres north of the equator. 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