One in two Americans is a Protestant

Combined, Protestants constitute more than half of the U.S. adult population, followed by Catholics who constitute nearly one-fourth. One in six adults is not affiliated with any religious tradition.

Religious affiliation as percentage of U.S. adult population in 2007

One in two Americans is a Protestant

Source: The Pew Forum on Religion and Public Life, U.S. Religious Landscape Survey, 2008.