Loudon is a town in Merrimack County, New Hampshire, United States. The population was 5,317 at the 2010 census. Loudon is the home of New Hampshire Motor Speedway.
According to the United States Census Bureau, the town has a total area of 47.5 square miles (123 km), of which 46.8 sq mi (121 km) is land and 0.7 sq mi (1.8 km) is water, comprising 1.41% of the town. The town’s highest point is near its northern border, where an unnamed summit just north of the location known as Sabattus Heights reaches 1,050 feet (320 m) above sea level.
As of the census of 2010, there were 5,317 people, 1,966 households, and 1,459 families residing in the town. There were 2,081 housing units, of which 115, or 5.5%, were vacant. The racial makeup of the town was 98.3% white, 0.3% African American, 0.3% Native American, 0.4% Asian, 0.0% Native Hawaiian or Pacific Islander, 0.1% some other race, and 0.8% from two or more races. 0.8% of the population were Hispanic or Latino of any race.
Of the 1,966 households, 34.3% had children under the age of 18 living with them, 62.0% were headed by married couples living together, 7.8% had a female householder with no husband present, and 25.8% were non-families. 18.6% of all households were made up of individuals, and 6.5% were someone living alone who was 65 years of age or older. The average household size was 2.70, and the average family size was 3.05.
In the town, 23.2% of the population were under the age of 18, 6.8% were from 18 to 24, 24.4% from 25 to 44, 34.3% from 45 to 64, and 11.2% were 65 years of age or older. The median age was 41.9 years. For every 100 females, there were 98.3 males. For every 100 females age 18 and over, there were 94.8 males.
For the period 2011-2015, the estimated median annual income for a household was $65,417, and the median income for a family was $72,266. Male full-time workers had a median income of $57,422 versus $41,201 for females. The per capita income for the town was $30,248. 11.8% of the population and 6.9% of families were below the poverty line. 13.5% of the population under the age of 18 and 3.0% of those 65 or older were living in poverty.