http://www.adherents.com/adh_branches.html
| Branch | Religion | Number of Adherents |
|---|---|---|
| Catholic | Christianity | 1,050,000,000 |
| Sunni | Islam | 940,000,000 |
| Vaishnavites | Hinduism | 580,000,000 |
| Orthodox/Eastern Christian | Christianity | 240,000,000 |
| Shaivites | Hinduism | 220,000,000 |
| Conservative Protestant | Christianity | 200,000,000 |
| Mahayana | Buddhism | 185,000,000 |
| Liberal Protestant | Christianity | 150,000,000 |
| Theravada | Buddhism | 124,000,000 |
| Shiite | Islam | 120,000,000 |
| African indigenous sects (AICs) | Christianity | 110,000,000 |
| Pentecostal | Christianity | 105,000,000 |
| Anglican | Christianity | 73,000,000 |
| Sikhism | Sikhism | 23,000,000 |
| neo-Hindus and reform Hindus | Hinduism | 22,000,000 |
| Lamaism (Vajrayana/Tibetan, etc.) | Buddhism | 20,000,000 |
| Jehovah's Witnesses | Christianity | 14,800,000 |
| Latter Day Saints | Christianity | 12,500,000 |
| Ahmadiyya | Islam | 10,000,000 |
| Veerashaivas (Lingayats) | Hinduism | 10,000,000 |
| Baha'i World Faith | Baha'i Faiths | 6,000,000 |
| Conservative | Judaism | 4,500,000 |
| Unaffiliated and Secular | Judaism | 4,500,000 |
| Svetambara | Jainism | 4,000,000 |
| Reform | Judaism | 3,750,000 |
| Seicho-No-Ie | New Japanese | 3,200,000 |
| Shinto all branches | Shinto | 3,000,000 |
| Tenrikyo | New Japanese | 2,800,000 |
| PL Kyodan | New Japanese | 2,600,000 |
| Orthodox | Judaism | 2,000,000 |
| New Thought (Unity, Christian Science, etc.) | Christianity | 1,500,000 |
| Sekai Kyuseikyo | New Japanese | 800,000 |
| Sthanakavasis | Jainism | 750,000 |
| Zenrinkai | New Japanese | 600,000 |
| Druze | Islam | 450,000 |
| Tensho Kotai Jingukyo | New Japanese | 400,000 |
| Friends (Quakers) | Christianity | 300,000 |
| Ennokyo | New Japanese | 300,000 |
| Digambaras | Jainism | 155,000 |
| Reconstructionist | Judaism | 150,000 |
| Parsis | Zoroastrianism | 110,000 |
| Gabars | Zoroastrianism | 20,000 |
The source site list the last update as of 28 October 2005, and so these are 2005 statistics. Please see my notes in comments.
