Arnold is a suburb of Annapolis and a census-designated place (CDP) in Anne Arundel County, Maryland, United States. The population was 23,106 at the 2010 census. Neighborhoods straddle College Parkway and Maryland Route 2 (Ritchie Highway). Arnold is located on the scenic Broadneck peninsula. The ZIP code is 21012.
Arnold is located at 39°2′50″N 76°29′48″W / 39.04722°N 76.49667°W / 39.04722; -76.49667 (39.047263, −76.496552). It is 5 miles (8 km) north of Annapolis, the state capital, and 24 miles (39 km) south of downtown Baltimore.
According to the United States Census Bureau, the CDP has a total area of 13.6 square miles (35.1 km), of which 10.8 square miles (28.0 km) is land and 2.7 square miles (7.1 km), or 20.18%, is water, consisting of the tidal Severn (to the southwest) and Magothy (to the northeast) rivers.
As of the census of 2010, there were 23,106 people, 8,373 households, and 6,396 families residing in the CDP. The population density was 2,168.7 people per square mile (837.3/km²). There were 8,623 housing units at an average density of 798.4 per square mile (308.3/km²). The racial makeup of the CDP was 88.65% White, 5.23% African American, 0.23% Native American, 2.41% Asian, 0.03% Pacific Islander, 1.16% from other races, and 2.28% from two or more races. Hispanic or Latino of any race were 3.97% of the population.
There were 8,373 households, of which 40.2% had children under the age of 18 living with them; 63.8% were married couples living together, 9.5% had a female householder with no husband present, and 23.6% were non-families. 4.6% had someone living alone who was 65 years of age or older. The average household size was 2.76 and the average family size was 3.15.
In the CDP, the population was spread out, with 25.31% under the age of 18, 6.1% from 18 to 24, 30.6% from 25 to 44, 26.9% from 45 to 64, and 8.6% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 93.9 males. For every 100 females age 18 and over, there were 90.1 males.
According to a 2007 estimate, the median income for a household in the CDP was $93,480, and the median income for a family was $106,327. Males had a median income of $52,345 versus $36,337 for females. The per capita income for the CDP was $31,236. About 2.0% of families and 3.0% of the population were below the poverty line, including 2.9% of those under age 18 and 3.5% of those age 65 or over.