Brooklyn (NYC borough) is 48% larger than San Francisco.
Area: 180 km2 calculated
Population: 2,565,635 (2012)
Brooklyn is the most populous of New York City's five boroughs, with about 2.6 million people, as well as the second-largest in area. Wikipedia
Area: 122 km2 calculated
Population: 825,863 (2012)
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