Holtsville is located in southeast New York. Holtsville is part of Suffolk County. Holtsville has 7.11 square miles of land area and has no water area. As of 2010-2014, the total Holtsville population is 20,054, which has grown 17.92% since 2000. The population growth rate is much higher than the state average rate of 3.26% and is much higher than the national average rate of 11.61%. Holtsville median household income is $92,730 in 2010-2014 and has grown by 35.29% since 2000. The income growth rate is about the same as the state average rate of 35.25% and is higher than the national average rate of 27.36%. Holtsville median house value is $346,000 in 2010-2014 and has grown by 102.10% since 2000. The house value growth rate is higher than the state average rate of 90.79% 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 Holtsville is better than the state average in quality. The Holtsville area code is 631.