Arnold is located close to the center of Maryland. Arnold is part of Anne Arundel County. Arnold has 10.82 square miles of land area and 2.73 square miles of water area. As of 2010-2014, the total Arnold population is 23,131, which has shrunk 1.24% since 2000. The population growth rate is much lower than the state average rate of 11.16% and is much lower than the national average rate of 11.61%. Arnold median household income is $105,250 in 2010-2014 and has grown by 42.23% since 2000. The income growth rate is about the same as the state average rate of 40.25% and is much higher than the national average rate of 27.36%. Arnold median house value is $381,700 in 2010-2014 and has grown by 109.27% since 2000. The house value growth rate is higher than the state average rate of 96.92% and is much higher 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 Arnold is better than the state average in quality. The Arnold area code is 410.