VAP population estimates are based on estimates of population change since the last census closely followed by the population estimates division at the Census Bureau. When a new census is conducted at the end of a decade, the population estimates are inevitably out of line with the actual census. The Census Bureau adjusts the previous decade's population estimates to conform with the new information revealed by the census. This is called the intercensal adjustment. Thus, we will not have a definitive estimate of the voting-age population and, by association, turnout rates in current decade's elections until the intercensal adjustment is released sometime after the end of this decade. In the meantime, the population estimates serve as the best estimate of the voting-age population of the United States.
Population estimates are available from the Census Bureau's website.
Although the VAP estimates presented on this website are based on official Census Bureau reports but they are not directly produced by the Census Bureau and -should not be cited as a Census Bureau product.