Kane County is a county in the U.S. state of Illinois. According to the 2010 census, it has a population of 515,269, making it the fifth-most populous county in Illinois. Its county seat is Geneva, and its largest city is Aurora.
According to the U.S. Census Bureau, the county’s area was 524 square miles (1,360 km), of which 520 square miles (1,300 km) is land and 4.1 square miles (11 km) (0.8%) is water. Its largest cities are along the Fox River.
As of the 2010 census, there were 515,269 people, 170,479 households, and 128,323 families residing in the county. The population density was 990.8 inhabitants per square mile (382.6/km). There were 182,047 housing units at an average density of 350.1 per square mile (135.2/km). The racial makeup of the county was 74.6% white, 5.7% black or African American, 3.5% Asian, 0.6% American Indian, 13.0% from other races, and 2.6% from two or more races. Those of Hispanic or Latino origin made up 30.7% of the population. In terms of ancestry, 24.3% were German, 13.0% were Irish, 7.9% were Polish, 7.4% were Italian, 7.1% were English, and 2.4% were American.
Of the 170,479 households, 42.3% had children under the age of 18 living with them, 59.2% were married couples living together, 11.0% had a female householder with no husband present, 24.7% were non-families, and 19.8% of all households were made up of individuals. The average household size was 2.98 and the average family size was 3.45. The median age was 34.5 years.
The median income for a household in the county was $67,767 and the median income for a family was $77,998. Males had a median income of $53,833 versus $39,206 for females. The per capita income for the county was $29,480. About 7.0% of families and 9.1% of the population were below the poverty line, including 13.5% of those under age 18 and 5.7% of those age 65 or over.