Rolla is located in Phelps county Missouri with a geographic area of 12.1 square miles. The total population in Rolla is 20,273 with 55.1% male and 44.9% female. Children under age 5 represent 5.4% of the population, under age 18 equal 17.2% of the population and over age 65 is 14.0% of the population. The median household income is $37,252, per capita income is $22,168. There are a total of 8,470 housing units with 40.6% owner occupied. Education includes 22.3% of residents that are high school graduates and 35.1% with a bachelor's degree or higher. The average temperature in Rolla in the summer is 76 degrees, and in the winter 32 degrees.