Decatur is a city located in Macon County Illinois. It is also the county seat of Macon County. With a 2020 population of 69,966, it is the 17th largest city in Illinois and the 533rd largest city in the United States . Decatur is currently declining at a rate of -0.55% annually and its population has decreased by -8.09% since the most recent census, which recorded a population of 76,122 in 2010. Decatur reached it's highest population of 93,939 in 1980. Spanning over 47 miles, Decatur has a population density of 1,653 people per square mile.
The average household income in Decatur is $59,490 with a poverty rate of 22.09%. The median rental costs in recent years comes to $683 per month, and the median house value is $83,000. The median age in Decatur is 40.2 years, 37.7 years for males, and 41.9 years for females.