Collinsville is located in southwest Illinois. Collinsville is between the Madison, Saint Clair county. Collinsville has 14.68 square miles of land area and 0.19 square miles of water area. As of 2010-2014, the total Collinsville population is 25,282, which has grown 2.33% since 2000. The population growth rate is lower than the state average rate of 3.62% and is much lower than the national average rate of 11.61%. Collinsville median household income is $52,821 in 2010-2014 and has grown by 24.72% since 2000. The income growth rate is higher than the state average rate of 22.70% and is lower than the national average rate of 27.36%. Collinsville median house value is $123,300 in 2010-2014 and has grown by 47.66% since 2000. The house value growth rate is higher than the state average rate of 34.33% and is about the same as the national average rate of 46.91%. As a reference, the national Consumer Price Index (CPI) inflation rate for the same period is 26.63%. On average, the public school district that covers Collinsville is worse than the state average in quality. The Collinsville area code is 618.