World Religions by Population

Muslims. Between 2010 and 2020 the number of Muslims rose by 347 million, more than all other religions combined, to about 2.0 billion. Their share of the world's population rose from 23.9% to 25.6%, the largest gain of any group [1][3]. Pew attributes this mainly to a young age structure and high fertility [2].

The religiously unaffiliated grew by 270 million to 1.9 billion, and their share rose to 24.2%. They were the only group besides Muslims to grow as a share of the world. Pew finds this growth comes from people raised in a religion, mainly Christians, leaving it, which outweighs the group's older age structure and low fertility [1][2].

Christians are still the largest group. Their number rose by 122 million to 2.3 billion, but their share fell by 1.8 points to 28.8%, because more people left Christianity than joined it [1][2]. Hindus grew in step with the world population and held steady at 14.9% [1]. Jews grew by almost 1 million to 14.8 million, about 0.2% of the world [1].

Buddhists were the only group whose numbers fell, by 19 million to 324 million, mostly in East Asia. Pew points to people leaving Buddhism there and to low birth rates in countries with older populations [1][4].

Pew built these figures from more than 2,700 censuses, surveys and population registers covering 201 countries and territories [6]. In this study it also revised its own earlier estimates for 2010: the religiously unaffiliated went from 16% to 23% of the world, and Buddhists from 7% to 5% [5]. Figures published before 2025, including older versions of this page, are not directly comparable.

Pew no longer reports folk and traditional religions as a separate group; they are now counted in "other religions", alongside Sikhs, Jains, Bahá'ís, Daoists, Shintoists, Zoroastrians and many smaller groups [6][5]. Other counts can run higher or lower, especially where people combine practices from more than one tradition, as is common in China and Japan.