Brentwood is located in Contra costa county California with a geographic area of 14.9 square miles. The total population in Brentwood is 63,013 with 47.9% male and 52.1% female. Children under age 5 represent 4.3% of the population, under age 18 equal 26.0% of the population and over age 65 is 15.0% of the population. The median household income is $113,298, per capita income is $42,300. There are a total of 20,410 housing units with 78.6% owner occupied. Education includes 17.6% of residents that are high school graduates and 40.5% with a bachelor's degree or higher. The average temperature in Brentwood in the summer is 73 degrees, and in the winter 43 degrees.