San Jose, California is 2.8 times larger than St. Petersburg, Florida.
Area: 470 km2 calculated
San Jose is the third-largest city in California, the tenth-largest in the United States, and the county seat of Santa Clara County. San Jose is the largest city within Silicon Valley, which is a major component of the greater Bay Area. It is the largest city in Northern California. Wikipedia
Area: 166 km2 calculated
St. Petersburg is a city in Pinellas County, Florida, United States. As of the 2013 census estimate, the population was 249,688, making St. Petersburg the 5th most populous city in the state of Florida and the largest city in Florida that is not a county seat. St. Wikipedia