Williamstown is located in southwest New Jersey. Williamstown is between the Gloucester, Atlantic county. Williamstown has 7.42 square miles of land area and 0.00 square miles of water area. As of 2010-2014, the total Williamstown population is 15,425, which has grown 30.59% since 2000. The population growth rate is much higher than the state average rate of 5.47% and is much higher than the national average rate of 11.61%. Williamstown median household income is $63,281 in 2010-2014 and has grown by 43.17% since 2000. The income growth rate is higher than the state average rate of 30.67% and is much higher than the national average rate of 27.36%. Williamstown median house value is $205,100 in 2010-2014 and has grown by 83.78% since 2000. The house value growth rate is about the same as the state average rate of 87.30% 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 Williamstown is close to the state average in quality. The Williamstown area code is 856.