From Census.gov - Apportionment is the process of dividing the 435 seats in the U.S. House of Representatives among the 50 states. The results of the census are used to determine the number of seats each state is entitled to, with each state being entitled to a minimum of one seat in the U.S. House of Representatives by default.
Adopted by Congress in 1941 and used for every U.S. census ever since, the method of equal proportions results in a listing of the states according to a priority value - calculated by dividing the population of each state by the geometric mean of its current and next seats - that assigns seats 51 through 435.
The last U.S. census prior to the 2020 census was conducted in 2010; thus, the following data indicates the number of seats a state has lost or gained upon completion of the 2020 census:
California: lost 1 seat
Colorado: gained 1 seat
Florida: gained 1 seat
Illinois: lost 1 seat
Michigan: lost 1 seat
Montana: gained 1 seat
New York: lost 1 seat
North Carolina: gained 1 seat
Ohio: lost 1 seat
Oregon: gained 1 seat
Pennsylvania: lost 1 seat
Texas: gained 2 seats
West Virginia: lost 1 seat
The following states have the most seats in the House of Representatives upon completion of the 2020 census:
California: 52 seats
Texas: 38 seats
Florida: 28 seats
New York: 26 seats
Illinois: 17 seats
Pennsylvania: 17 seats
Ohio: 15 seats
Georgia: 14 seats
North Carolina: 14 seats
Michigan: 13 seats
New Jersey: 12 seats
Washington: 10 states
The following states have the least amount of seats in the House of Representatives with only one seat per state upon completion of the 2020 census:
Alaska
Delaware
North Dakota
South Dakota
Vermont
Wyoming
The following states saw the greatest increase in population size by percent from the 2010 census to the 2020 census:
Utah: 18.4% population increase
Idaho: 17.4% population increase
Texas: 15.9% population increase
North Dakota: 15.8% population increase
Nevada: 15% population increase
Colorado 14.8% population increase
Florida: 14.6% population increase
Washington: 14.6% population increase
Arizona: 11.9% population increase
South Carolina: 10.7% population increase
Georgia: 10.6% population increase
Oregon: 10.6% population increase
Delaware: 10.2% population increase
The following states saw a decrease in population size by percent from the 2010 census to the 2020 census:
West Virginia: 3.2% population decrease
Mississippi: 0.2% population decrease
Illinois: 0.1% population decrease
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