American Community Survey

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Guidance for Data Users Main

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Three tips for using American Community Survey (ACS) data

1. The 2010 Census shows the number of people who live in the U.S. and the American Community Survey shows how people live.

   Use data from the American Community Survey to obtain demographic, social, economic, and housing characteristics.

   Use numbers from the 2010 Census to obtain counts of the population and their basic characteristics (sex, age, race, Hispanic origin, and homeowner status).

   Use data from the Census Bureau's Population Estimates Program in the years between censuses. The Census Bureau's Population Estimates Program produces official population estimates for the nation, states, counties, cities and towns, plus housing unit estimates for states and counties.

2. All American Community Survey data are estimates.

   The Census Bureau collects American Community Survey data from a sample of the population in the United States and Puerto Rico--rather than from the whole population. All ACS data are survey estimates. To help you interpret the reliability of the estimate, the Census Bureau publishes a margin of error (MOE) for every ACS estimate.

3. American Community Survey collects and releases data by the calendar year for geographic areas that meet specific population thresholds.

   Data collected between...	Data pooled to produce	Data published for areas with
   January 1, 2011 and December 31, 2011	2011 ACS 1-year estimates	populations of 65,000+
   January 1, 2009 and December 31, 2011	2009-2011 ACS 3-year estimates	populations of 20,000+
   January 1, 2007 and December 31, 2011	2007-2011 ACS 5-year estimates	populations of almost any size

   American Community Survey 1-, 3-, and 5-year estimates are period estimates, which means they represent the characteristics of the population and housing over a specific data collection period. Data are combined to produce 12 months, 36 months or 60 months of data. These are called 1-year, 3-year and 5-year data.