San Francisco, CA has a population of 850,282 and is the 13th largest city in the United States. The population density is 18,128 per sq mi which is 7700% higher than the California average and 19908% higher than the national average. The median age in San Francisco is 38 which is approximately 7% higher than the California average of 36. In San Francisco, 45% of the population over 15 years of age are married, 56% speak English and 11% speak Spanish. 39% of San Francisco residents were born in California, 24% were born out of state, 2% were born outside of the United States and 35% were foreign born.