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Congressional Apportionment

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How It's Calculated

The Constitution provides that each state will have a minimum of one member in the U.S. House of Representatives, and then the apportionment calculation divides the remaining 385 seats among the 50 states. Congress decides the method used to calculate the apportionment.

The method for calculating the apportionment has changed over time. The methods used through most of the 20th century have been based upon the use of a mathematically determined priority listing of states. Adopted by Congress in 1941 and used each census thereafter, the method of equal proportions also 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 method of equal proportions is calculated according to provisions of Title 2, U.S. Code.

For a technical description of how the method of equal proportions was used in developing the apportionment counts, see Computing Apportionment.


Source: U.S. Census Bureau | Congressional Apportionment |  Last Revised: 2013-02-04T07:44:34.737-05:00