What year is your data from?
With the release of the 2020 5-year estimates, our data is the most current set available. We also offer data for 2019 states and cities at a reduced price.
Where does the data come from?
The data comes from the American Community Survey, a demographics survey program run by the United States Census Bureau. We gather this data directly from data.census.gov and refine it to be accurate and clearer to read. For more information on the ACS’s process, you can read their 2020 Subject Definitions here.
How do I know if this data is any good (reliable)?
One great feature of this census data is that margins of error are included, so you'll know how confident you can be in the provided estimates. Margins of error are + or - the estimate value. For the 2020 set, some fields can seem off due to a technique known as Differential Privacy. This is new for the 2019/2020 Census Data, and is done by the Census Bureau itself. This should only apply to areas small enough that the information for a column would be a potential identifier, betraying a citizen's privacy.
What's a ZCTA, and how's it different from a ZIP code?
Since the demographic data on this website is from the U.S. Census Bureau, we’re using the U.S. Census Bureau’s ZIP Code Tabulation Areas (ZCTAs). ZCTAs are generalized area representations of the United States Postal Service (USPS) ZIP code service areas, but are not the same as ZIP codes. A ZIP code is technically a linear postal route. This means that using a ZIP code is impractical when it comes to census surveys.
Sometimes, there isn’t a ZCTA for a certain ZIP code. Examples of such ZIP codes that we’ve run into in the past include a ZIP only for the IRS, a ZIP that is a single office building, or a ZIP code with a small population - or no population at all. And sometimes there aren't enough samples in a ZIP/ZCTA to produce an estimate (i.e. small population).
Is there a ZIP code to ZCTA crosswalk?
If you're downloading the data after purchase, we don't have a tool handy - but they do exist elsewhere.
How many ZCTAs/ZIPs are in your data?
Last we checked, it's approximately around 32,989 ZCTAs. Some of these do not have estimates (null) or have estimates of $0.
What does "in 2019/2020 inflation-adjusted dollars" mean?
You may be familiar with the U.S. Census Bureau's Decennial Census (2010) that sends a survey out to all US households. What's not as well known is that the U.S. Census Bureau also collects data each year from a much smaller sample of U.S. households, and they use this annual data to produce a dataset called the American Community Survey. Now, because the sample size of the American Community Survey is small, the Census Bureau can only produce annual demographic estimates for large geographies like New York City or Harris County, Texas. For small geographies like ZIP codes/ZCTAs, they have to sum the survey data that's collected in multiple years to produce estimates with reasonable margins of error.
The U.S. Census Bureau has taken American Community Survey data collected over the past five years, and uses this data to produce demographic estimates for ZIP codes/ZCTAs for 2020. When the Census Bureau collects income data in 2016 and then they use the 2016 data to estimate the 2020 income, they need to adjust the income reported in 2016 to 2020 dollars to account for inflation.