American Community Survey (Annual Data)
The U.S. Census Bureau’s American Community Survey (ACS) provides annual demographic data including educational attainment, foreign born population, language spoken at home, household income, and housing characteristics.
When using the American Community Survey’s data, it is best to use percentages rather than report actual numbers because the ACS is a survey of a small subset of the county’s population.
Census Bureau data, including data from the ACS, can be found on the Census Bureau’s data website.
ACS One-Year Estimates
- Best to use if current data is needed, but be aware it has large statistical sample error
- Available countywide
- Not available for county sub-geographies (e.g. towns, election districts)
ACS Five-Year Estimates
- Available for county sub-geographies
- Use for increased statistical reliability
2010 Decennial Census
The U.S. Census Bureau’s Decennial Census is conducted every ten years to count 100% of the county’s population. Census 2010 data can be found on the U.S. Census Bureau’s data website by typing “2010 Decennial Census Loudoun County, Virginia” in the search box.
2020 Decennial Census
Data from the 2020 Decennial Census is available on the U.S. Census Bureau’s data website. Find more information about the 2020 Decennial Census data here.