Get the Data
- Access all of the data via data.census.gov.
Find out when to use 1-year vs. 5-year estimates. For those who want more detail on the methods used to collect the data and insights on margins of error, use of small area data and other topics, your best bet is the ACS website.
Margins of Error and Statistical Significance
- Online ACS Calculator: This tool can test for significance or compute a value from 2 existing values (e.g., a percentage of total)
- ACS Statistics Calculator: This spreadsheet makes it easier to calculate margins of error and statistical significance from ACS estimates.
- The Search for Significance: A Crash Course in Statistical Significance: A brief tutorial about margins of error and statistical significance and how they relate to the ACS (InContext: Nov-Dec 2008).
Fast Facts on the ACS Estimates
The 2018 ACS 1-year estimates are based on data collected between January 2018 and December 2018.
- Published for selected geographic areas with populations of 65,000 or greater
- Represent the average characteristics over calendar year
- Have smaller sample size than the 5-year estimates
- Are more current than the 5-year estimates
The 2014-2018 ACS 5-year estimates are based on data collected between January 2014 and December 2018.
- Published for small geographic areas
- Represent the average characteristics over the 5-year period of time
- Have larger sample size than the 1-year estimates
- Are less current than the 1-year estimates
Comparing to Prior Census Data
The 5-year estimates (and the other years from ACS) are not always comparable to the long-form data from previous censuses. Here are some tools to help find comparable tables between the ACS and decennial data.