As of the census of 2000, there were 46,229 people, 15,654 households, and 12,241 families residing in the city. The population density was 2,700.3/km² (6,991.1/mi²). There were 16,028 housing units at an average density of 936.2/km² (2,423.9/mi²). The racial makeup of the city was 65.61% White, 20.81% Asian, 0.40% Pacific Islander, 2.77% Black or African American, 0.59% Native American, 5.44% from other races, and 4.38% from two or more races. 15.65% of the population were Hispanic or Latino.
There were 15,654 households out of which 38.8% had children under the age of 18 living with them, 60.0% were married couples living together, 13.3% had a female householder with no husband present, and 21.8% were non-families. 17.6% of all households were made up of individuals and 6.6% had someone living alone who was 65 years of age or older. The average household size was 2.93 and the average family size was 3.31.
In the city the population was spread out with 27.0% under the age of 18, 7.9% from 18 to 24, 30.2% from 25 to 44, 24.4% from 45 to 64, and 10.6% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 94.9 males. For every 100 females age 18 and over, there were 90.5 males.
The median income for a household in the city was $64,377, and the median income for a family was $70,060 (these figures had risen to $80,331 and $86,286 respectively as of a 2007 estimate). Males had a median income of $50,781 versus $36,337 for females. The per capita income for the city was $25,798. About 4.6% of families and 6.0% of the population were below the poverty line, including 7.2% of those under age 18 and 5.1% of those age 65 or over.
The 2008 population estimated by the California Department of Finance was 49,541.