The American Community Survey (ACS) was created to replace the decennial census "long-form" questionnaire. It has been generating annual estimates since its inception in 2005. Similar to the "long form", the ACS gathers comprehensive socio-economic data. Unlike the decennial census, which aimed to provide a snapshot of the population at a single point in time, the ACS primarily describes demographic and socio-economic characteristics over a span of time. Currently, the ACS offers two main sets of data: one-year estimates and five-year estimates. Data users should not mix these two data sets. Data users should also carefully examine the margin of error (MOE) to determine the reliability of data when drawing conclusions on statistical differences.
The one-year American Community Survey (ACS) data offers the most up-to-date information available. These one-year ACS datasets provide information for areas with populations of 65,000 persons or more. The one-year estimates are best used when data currency is more important than precision, and when analyzing large populations. The links below provide data specific to Fairfax County as a whole.
The five-year American Community Survey (ACS) estimates encompass data collected over a span of 60 months. As an illustration, the 2017-2021 ACS 5-year estimates compiled information from January 1, 2017, to December 31, 2021. These five-year estimates are more reliable than one-year estimates and are applicable to small geographical areas, such as the census tract and census block groups that one-year estimates are not available. The five-year estimates are best used when data precision is prioritized over currency and when analyzing very small populations. The links below provide data specific to Fairfax County as a whole.
The Census Reporter, Geography Profile, and Narrative Profile icons connect to the user-friendly interfaces for Fairfax County using the most recent Decennial Census & ACS data, provided by the U.S. Census Bureau.
Census Reporter offers a user-friendly interface to visualize the latest one-year ACS data on various topics, designed to make it easier for journalists to write stories using information from the U.S. Census Bureau.
Data Profile summarizes the data for a single geographic area, in both numbers and percentages, to cover the most frequently requested social, economic, housing, and demographic data.
Narrative Profile provides short, analytic reports derived from the ACS five-year estimates, covering 18 different topic areas for a selected geographic area.