Foster City is a city located in California. With a 2020 population of 33,485, it is the 227th largest city in California and the 1177th largest city in the United States. Foster City is currently declining at a rate of -0.62% annually but its population has increased by 9.55% since the most recent census, which recorded a population of 30,567 in 2010. Foster City reached it's highest population of 34,292 in 2017. Spanning over 20 miles, Foster City has a population density of 8,821 people per square mile.
The average household income in Foster City is $185,716 with a poverty rate of 4.35%. The median rental costs in recent years comes to $3,209 per month, and the median house value is $1.25 Mn. The median age in Foster City is 40 years, 38.3 years for males, and 41.6 years for females. For every 100 females there are 99.3 males.