Allen is located in northeast Texas. Allen is part of Collin County. Allen has 26.29 square miles of land area and 0.10 square miles of water area. As of 2010-2014, the total Allen population is 89,845, which has grown 106.28% since 2000. The population growth rate is much higher than the state average rate of 25.13% and is much higher than the national average rate of 11.61%. Allen median household income is $102,120 in 2010-2014 and has grown by 29.39% since 2000. The income growth rate is lower than the state average rate of 31.68% and is higher than the national average rate of 27.36%. Allen median house value is $207,400 in 2010-2014 and has grown by 45.65% since 2000. The house value growth rate is lower than the state average rate of 59.27% 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 Allen is much better than the state average in quality. The Allen area codes are 214, 469, 972.