Northbrook is an affluent suburb of Chicago, located at the northern edge of Cook County, Illinois, United States.
Northbrook is located at 42°7′45″N 87°50′27″W / 42.12917°N 87.84083°W / 42.12917; -87.84083 (42.129226, −87.840715).
According to the 2010 census, Northbrook has a total area of 13.255 square miles (34.33 km), of which 13.19 square miles (34.16 km) (or 99.51%) is land and 0.065 square miles (0.17 km) (or 0.49%) is water.
Although it is debated, many people consider Northbrook to be a part of the towns in the North Shore (Chicago).
As of the census of 2010, there were 33,170 people, 12,642 households, and 9,522 families residing in the village. The population density was 2,514.8 people per square mile (971.0/km). There were 13,434 housing units at an average density of 1,018.5 per square mile (392.8/km). The racial makeup of the village was 86.1% White, 0.6% African American, 0.04% Native American, 11.7% Asian, 0.01% Pacific Islander, 0.4% some other race, and 1.2% from two or more races. Hispanic or Latino of any race were 2.5% of the population.
There were 12,642 households, out of which 32.5% had children under the age of 18 living with them, 67.3% were headed by married couples living together, 6.1% had a female householder with no husband present, and 24.7% were non-families. 22.5% of all households were made up of individuals, and 14.6% were someone living alone who was 65 years of age or older. The average household size was 2.57, and the average family size was 3.03.
In the village, the population was spread out with 23.5% under the age of 18, 4.9% from 18 to 24, 17.0% from 25 to 44, 32.2% from 45 to 64, and 22.4% who were 65 years of age or older. The median age was 48.0 years. For every 100 females, there were 91.7 males. For every 100 females age 18 and over, there were 88.0 males.
For the period 2009–11, the estimated median annual income for a household in the village was $103,053, and the median income for a family was $166,083. Male full-time workers had a median income of $97,459 versus $54,970 for females. The per capita income for the village was $51,719. About 4.1% of families and 4.8% of the population were below the poverty line, including 4.6% of those under age 18 and 6.0% of those age 65 or over.