There are approximately 4,200 to 10,000 distinct religions worldwide, though the exact number varies depending on definitions and classifications used by experts

. Most of these religions have relatively small, regionally based followings

. The vast majority of the global population adheres to a few major religions. Over 85% of people worldwide identify with a religious group, with Christianity, Islam, Hinduism, and Buddhism being the four largest religions, collectively accounting for over 77% of the global population

. Christianity alone has about 2.6 billion adherents, Islam nearly 2 billion, Hinduism around 1.1 billion, and Buddhism about 500 million

. In summary:

• Estimated total number of religions: 4,200 to 10,000+
• Major religions by population: Christianity, Islam, Hinduism, Buddhism
• Over 85% of the world population identifies with a religion

This wide diversity includes many smaller and indigenous religions, new religious movements, and various sects within the major faiths.