San Marino is a city located in California. With a 2020 population of 12,870, it is the 344th largest city in California and the 2580th largest city in the United States. San Marino is currently declining at a rate of -0.69% annually and its population has decreased by -2.11% since the most recent census, which recorded a population of 13,147 in 2010. San Marino reached it's highest population of 14,177 in 1970. Spanning over 4 miles, San Marino has a population density of 3,418 people per square mile.
The average household income in San Marino is $232,829 with a poverty rate of 6.70%. The median rental costs in recent years comes to $3,293 per month, and the median house value is $2.00 Mn. The median age in San Marino is 46.9 years, 44.7 years for males, and 48.3 years for females. For every 100 females there are 96.5 males.