Tennessee’s center of population remains located on the outskirts of Murfreesboro in Middle Tennessee, but continued drifting northeast after 2020 Census data was used to compute an updated location.

The new center is 1.75 miles away from the 2010 location, which also was found in central Rutherford County. The shift reflects slower growth in the western third of the state where more than a dozen counties lost population, as well as increases in the middle and eastern thirds.

Data showing the new center was released by the U.S. Census Bureau on November 5, 2021.

A new interactive website from the Tennessee State Data Center shows the movement of each state and county center between 2000 and 2020. It also provides data and maps highlighting the amount and percent of population change since 2010, which is important in interpreting why a population center has moved.

This interactive application shows the mean center of population for each state and county in the United States in 2000, 2010 and 2020. It visualizes the degree of population shift decade by showing lines connecting the center to its prior location.

How is the center of population determined?

The population center is the point where a flat and rigid representation of the state would balance if identical weights for each person were placed at their residence. Centers can be calculated for the U.S. as a whole or smaller areas, such as individual counties.

The point’s movement over time helps to illustrate the relative strength of population trends, including areas losing or gaining residents. For example, the U.S. center of population has moved westward each decade since 1790 as the country was settled and more recently has shown movement in a southerly direction as growth in the southern half of the U.S. has accelerated.

The Census Bureau calculates the center of population using tabulation blocks from the decennial census. Blocks are the smallest geographic area at which population data are reported and are usually bounded by physical features like streets or other political boundaries.

Tennessee’s center was calculated using the average (mean) latitude and longitude for each of the state’s 178,000 census blocks. Each block is weighted equivalent to its total population, which produces a weighted mean center. Between decades, the changing weights cause the center to move.

In 2020, over 8 million census blocks were used in the calculation of U.S., state and county centers of population.