Demographics

As of the 2010 census,^[53] there were:

• 207,627 people
• 98,050 households,
• and 41,607 families residing in Arlington.

The population density was 8,309 people per square mile (2,828/km²),^[54] the highest of any county in Virginia.
According to the US Census, the racial makeup of the county in 2012 was:

• 63.8% non-Hispanic White
• 8.9% Non-Hispanic Black or African American
• 0.8% Non-Hispanic Native American
• 9.9% Non-Hispanic Asian (2.0% Indian, 1.7% Chinese, 1.1% Filipino, 0.9% Korean, 0.7% Vietnamese, 2.7% Other Asian)
• 0.1% Pacific Islander
• 0.29% Non-Hispanic other races
• 3.0% Non-Hispanics reporting two or more race
• 15.4% of the population was Hispanic or Latino of any race (3.4% Salvadoran, 2.0% Bolivian, 1.7% Mexican, 1.5% Guatemalan, 0.8% Puerto Rican, 0.7% Peruvian, 0.6% Colombian)
• 28% of Arlington residents were foreign-born as of 2000.
• Demographics courtesy of U.S. Census Quickfacts

Arlington has a high concentration of Halloween celebrators.^[55]

Low-rise residential structures help make up the real estate inventory in Arlington.

There were 86,352 households out of which 19.30% had children under the age of 18 living with them, 35.30% were married couples living together, 7.00% had a female householder with no husband present, and 54.50% were non-families. 40.80% of all households were made up of individuals and 7.30% had someone living alone who was 65 years of age or older. The average household size was 2.15 and the average family size was 2.96.
Families headed by single parents was the lowest in the DC area, under 6%, as estimated by the Census Bureau for the years 2006–2008. For the same years, the percentage of people estimated to be living alone was the third highest in the DC area, at 45%.^[56] In 2009, Arlington was highest in the Washington DC Metropolitan area for percentage of people who were single – 70.9%. 14.3% were married. 14.8% had families.^[5] In 2014 Arlington had the 2nd highest concentration of roommates after San Francisco among the 50 largest U.S. cities.^[57]
According to a 2007 estimate, the median income for a household in the county was $94,876, and the median income for a family was $127,179.^[58] Males had a median income of $51,011 versus $41,552 for females. The per capita income for the county was $37,706. About 5.00% of families and 7.80% of the population were below the poverty line, including 9.10% of those under age 18 and 7.00% of those age 65 or over.
The age distribution was 16.50% under 18, 10.40% from 18 to 24, 42.40% from 25 to 44, 21.30% from 45 to 64, and 9.40% who were 65 or older. The median age was 34 years. For every 100 females there were 101.50 males. For every 100 females age 18 and over, there were 100.70 males.
CNN Money ranked Arlington as the most educated city in 2006 with 35.7% of residents having held graduate degrees. Along with five other counties in Northern Virginia, Arlington ranked among the twenty American counties with the highest median household income in 2006.^[59] In 2009, the county was second in the nation (after nearby Loudoun County) for the percentage of people ages 25–34 earning over $100,000 annually (8.82% of the population).^{[5] [60]} In August 2011, CNN Money ranked Arlington seventh in the country in its listing of "Best Places for the Rich and Single."^[61]
In 2008, 20.3% of the population did not have medical health insurance.^[62] In 2010, AIDS prevalence was 341.5 per 100,000 population. This was eight times the rate of nearby Loudoun County and one-quarter the rate of the District of Columbia.^[63]
Crime statistics for 2009 included the report of 2 homicides, 15 forcible rapes, 149 robberies, 145 incidents of or aggravated assault, 319 burglaries, 4,140 incidents of larceny, and 297 reports of vehicle theft. This was a reduction in all categories from the previous year.^[64]