The World’s Religions

By the estimate of the Pew Research Center, published in June 2025, 2.3 billion of the world’s 7.9 billion people were Christians in 2020, 2.0 billion were Muslims, 1.9 billion identified with no religion, 1.2 billion were Hindus, 324 million were Buddhists and 14.8 million were Jews. Another 172 million belonged to other religions, among them Sikhs, Daoists, Jains, Baha’is, Shintoists and Zoroastrians. The share of people with any religion fell from 76.7% in 2010 to 75.8% in 2020, in the same report (Exhibit 1).

The figures come from more than 2,700 censuses, surveys and population registers covering 201 countries and territories, according to the dataset’s documentation. This overview sets out who believes what and where, how the faiths began, why the Pew and Gordon-Conwell counts disagree, and what is moving the numbers. Seven parts follow, one each on Christianity, Islam, Hinduism, Buddhism, Taoism and Chinese religion and Judaism, and one on religions that ended.

Where the faiths began

The carved stone enclosures of Göbekli Tepe, in southeastern Türkiye, are dated to the 9th–10th millennium BCE by Encyclopaedia Britannica and to 9600–8200 BCE by UNESCO. The religions with the most followers in 2020, in Pew’s count, trace their founders or first texts to later dates. Hinduism’s oldest text, the Rigveda, is dated to about 1500 BCE; the Buddha to c. 6th–4th century BCE; Confucius to 551–479 BCE; Jesus’s crucifixion to c. 30 CE; and Muhammad’s first revelation, by Muslim tradition as Britannica reports it, to 610. Exhibit 2 sets eighteen traditions on one axis, from Egyptian and Mesopotamian religion to the Sikh and Baha’i faiths, using the dates given by the reference works linked in its source line.

For several founders Britannica gives a range or a traditional date: the Buddha c. 6th–4th century BCE; Zoroaster traditionally c. 628–c. 551 BCE, noting that some modern scholars place him around 1200 BCE; Mahavira about 599 BCE, a date it says many scholars believe may be as much as 100 years early. Where a reference work gives a range, the chart starts the bar at the early end and marks it as approximate.

Who believes what, and where

Religious groups are concentrated. In Pew’s 2020 estimates, Christians make up more than half the population in most of the Americas, Europe, southern and central Africa and Oceania; Muslims in a band from West Africa through the Middle East to Indonesia; Hindus in India and Nepal; Buddhists in four countries of mainland Southeast Asia and in Sri Lanka, Bhutan and Mongolia. The unaffiliated are a majority in China, Japan, North Korea, Vietnam, Hong Kong, Macao and the Czech Republic, and since 2010 in the Netherlands, Uruguay and New Zealand (Exhibit 3).

Counted by majority, Christians led in 120 of the 201 places in 2020, down from 124 in 2010, by Pew’s count; Muslims in 53; the unaffiliated in 10. Israel is the one Jewish-majority country and Taiwan the one place where Pew’s “other religions,” mostly Daoist and folk religion there, are a majority (Exhibit 4).

A century of counts

Pew’s country series starts in 2010. For longer runs, one published series is the World Christian Database of the Center for the Study of Global Christianity at Gordon-Conwell Theological Seminary, which publishes world totals for 1900, 1970, 2000, 2020 and 2025 and a projection to 2050. By that count the number of Christians rose from 558 million in 1900 to 2.65 billion in 2025 and Muslims from 200 million to 2.06 billion. The largest change in proportion was among the nonreligious, from 3.3 million to 907 million; most of that rise came before 1970 (Exhibit 5).

The two sources disagree. For 2020 Gordon-Conwell counts 2.52 billion Christians against Pew’s 2.27 billion, 531 million Buddhists against 324 million, and 898 million agnostics and atheists against Pew’s 1.91 billion unaffiliated (Exhibit 6). The two count different things. Gordon-Conwell defines Christians as professing Christians plus secret believers and counts 453 million Chinese folk-religionists as a separate group; Pew counts the identity people report in censuses and surveys, and in China most adults report none (Pew, 2023). The part on Taoism and Chinese religion sets the Chinese survey measures side by side.

What moves the numbers

Pew attributes the changes between 2010 and 2020 to two forces: births and deaths, and people leaving or joining a religion. On switching, its surveys of adults ages 18 to 54 in 117 places find that for every adult who joined a religion after being raised with none, 3.2 left religion; Christians lost 3.1 for every one who joined, and Buddhists 1.8 (Exhibit 7).

On births, age matters. Muslims had a median age of 24.1 years in 2020 against 30.6 for the world, and Buddhists 39.8 (Exhibit 8). A younger group has more people entering childbearing years, which Pew identifies as the main source of Muslim growth; the unaffiliated grew in the decade despite an older age profile, which Pew’s report attributes mainly to people “shedding their religious identity after having been raised as Christians” (2025 report, p. 13).

The parts

• Christianity: the branches dated from 431 to 1906, and the shift of Christians to the Global South, 1900–2025, in the World Christian Database.
• Islam: the expansion from 622 to 751, Sunni and Shia in Pew’s 2009 estimate, and where Muslims lived in 2020.
• Hinduism: dated texts and teachers from about 1500 BCE, India’s census from 1951 to 2011, and Hindus outside India in 2020.
• Buddhism: the spread across Asia and the decline from 2010 to 2020.
• Taoism and Chinese religion: texts from about 300 BCE, the schools, and why Chinese surveys of 2016–2018 (CGSS, CFPS) give answers from under 0.5% to 75%.
• Judaism: world Jewish population from 1880 to 2024, Israel and the United States, and the branches.
• Religions that ended: dated endings from 75 CE to 1697 in Egypt, Mesopotamia, Rome, the Manichaean world, Scandinavia and the Americas, and the Zoroastrians counted in 2004 and 2012.