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The U.S. divided in thirds by population density

One third of the U.S. population lives in high density block groups, or no more than 0.33% of the total land area of the United States.1


population densities of over 4,965 people per square mile
One third of the U.S. population lives in medium density block groups, or no more than 1.27% of the total land area of the United States.1


population densities of 1,205 - 4,965 people per square mile
One third of the U.S. population lives in low density block groups, or as much as 98.31% of the total land area of the United States.1


population densities of under 1,205 people per square mile
Using the 2017-2021 American Community Survey 5-year Estimates, all U.S. Census block groups were sorted by population density and then divided in thirds with each third having approximately equal population of about 110 million.
The chart above represents the total population in low, medium and high density block groups since 2010, based on 2021 thresholds.

Note: Block group boundaries remained relatively consistent from 2010-2019, but where then redrawn following the decenial census in 2020.

By State

Below is the 2021 composition of high, medium and low density block groups by state and the rate of growth since 2010.
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1 U.S. Census block groups may contain non-residential land area such as industrial parks, shopping malls and national parks so portions of the block group may contain zero population.