According to the 2020 Census, Cobb has second highest Diversity Index in Georgia

screenshot of Georgia diversity index map with Cobb selectedScreenshot of the Georgia Diversity Index map with Cobb selected.

According to the U.S. Census Bureau, Cobb County has the second highest Diversity Index in Georgia, with Gwinnett County at the top of the index.

The Diversity Index is measured by determining the likelihood that two people chosen at random will be of different race or ethnicity (for further details see the full definition at the bottom of this article).

The top five counties by this measure are:

  1. Gwinnett County 75.1 percent
  2. Cobb County 67.3 percent
  3. Liberty County 67.1 percent
  4. Stewart County 66.8 percent
  5. Fulton County 66.5 percent

The bottom five (from lowest index to highest) are:

  1. Fannin County 14.7 percent
  2. Union County 15.3 percent
  3. Towns County 15.5 percent
  4. Dade County 17.0 percent
  5. Pickens County 17.5 percent

The overall Diversity Index for Georgia is 64.1 percent, tied with Florida, and second only to Texas (which stands at 67 percent) among southern states.

National Map of Diversity Index

Racial and Ethnic Diversity Index by State: 2020[Source: U.S. Census Bureau]

Census Bureau definition of Diversity Index

In a blog post on the U.S. Census Bureau website, the Diversity Index is defined as follows:

One of the measures we will use to present the 2020 Census results is the Diversity Index, or DI. This index shows the probability that two people chosen at random will be from different race and ethnic groups.

The DI is bounded between 0 and 1, with a zero-value indicating that everyone in the population has the same racial and ethnic characteristics, while a value close to 1 indicates that everyone in the population has different characteristics.

We converted the probabilities into percentages to make the results easier to interpret. In this format, the DI tells us the chance that two people chosen at random will be from different racial and ethnic groups.

September release of more detailed data

The 2020 data that the U.S. Census Bureau has released so far is the data needed by states for reapportionment. The bureau expects to release more detailed data in September, and then the public can access the data through much easier-to-use tools at