Christianity: 2.1 billion Islam: 1.3 billion Secular/Nonreligious/Agnostic/Atheist: 1.1 billion Hinduism: 900 million Chinese traditional religion: 394 million Buddhism: 376 million primal-indigenous: 300 million African Traditional & Diasporic: 100 million Sikhism: 23 million Juche: 19 million Spiritism: 15 million Judaism: 14 million Baha'i: 7 million Jainism: 4.2 million Shinto: 4 million Cao Dai: 4 million Zoroastrianism: 2.6 million Tenrikyo: 2 million Neo-Paganism: 1 million Unitarian-Universalism: 800 thousand Rastafarianism: 600 thousand Scientology: 500 thousand A major source for these estimates is the detailed country-by-country analysis done by David B. Barrett's religious statistics organization, whose data …showed first 75 words of 323 total…

…showed last 75 words of 323 total…additional input. The Adherents.com collection of religious adherent statistics now has over 43,000 adherent statistic citations, for over 4,300 different faith groups, covering all countries of the world. This is not an absolutely exhaustive compilation of all such data, but it is by far the largest compilation available on the Internet. Various academic researchers and religious representatives regularly share documented adherent statistics with Adherents.com so that their information can be available in a centralized database.