How often is the number of members representing each state in the House of Representatives recalculated?

Answer 1

Representatives are apportioned to the states on the basis of their population count as a percentage of the total US population at the end of a census year. The US Census conducts this count every ten years, and reapportionment occurs when states gain or lose a statistically significant number of residents (there is no fixed number). Changes become effective at the beginning of the next session of Congress.

The most recent census year was 2010; reapportionment of the House became effective in the first Session of the 112th Congress, in January 2011.

Answer 2

Every ten years after the census, the Census Bureau decides the number of representatives each state should have based on the population. The President then gives it to Congress. If nobody disagrees with the plan, it is put into effect.

Answer 3

Every ten years, after every U.S. Census, the 435 House seats are reapportioned based on the new census figures.