Gardner is located in east Kansas. Gardner is part of Johnson County. Gardner has 10.12 square miles of land area and 0.05 square miles of water area. As of 2010-2014, the total Gardner population is 20,128, which has grown 114.22% since 2000. The population growth rate is much higher than the state average rate of 7.24% and is much higher than the national average rate of 11.61%. Gardner median household income is $65,938 in 2010-2014 and has grown by 29.78% since 2000. The income growth rate is higher than the state average rate of 27.69% and is higher than the national average rate of 27.36%. Gardner median house value is $159,500 in 2010-2014 and has grown by 36.21% since 2000. The house value growth rate is much lower than the state average rate of 54.97% and is lower than 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 Gardner is much better than the state average in quality. The Gardner area code is 913.