Buffalo Grove is a city located in Cook County, Illinois. With a 2020 population of 40,387, it is the 40th largest city in Illinois and the 972nd largest city in the United States. Buffalo Grove is currently declining at a rate of -0.57% annually and its population has decreased by -2.67% since the most recent census, which recorded a population of 41,496 in 2010. Buffalo Grove reached it's highest population of 42,909 in 2000. Spanning over 10 miles, Buffalo Grove has a population density of 4,258 people per square mile.
The average household income in Buffalo Grove is $139,396 with a poverty rate of 4.39%. The median rental costs in recent years comes to $1,599 per month, and the median house value is $324,600. The median age in Buffalo Grove is 41.9 years, 40.5 years for males, and 43 years for females. For every 100 females there are 95.5 males.