This report surveys the eight major world religious categories — Christianity, Islam, Hinduism, Buddhism, Judaism, Sikhism, and two secular categories (the religiously unaffiliated/atheist/agnostic) — using the most current data from the Pew Research Center, the World Population Review, and other authoritative demographic sources. For each religion, it identifies global adherent counts, American adherent counts, the percentage of Americans who practice non-Christian faiths, the countries where each religion is the dominant majority, and the percentage of Christians residing within those non-Christian-majority nations.
Global Religious Population at a Glance (2020–2025)
The most recent Pew Research Center analysis of the global religious landscape, covering 201 countries and tracking changes from 2010 to 2020, found the following distribution:
Note: The “Unaffiliated” category includes atheists, agnostics, and those who identify with no organized religion — it is the world’s third-largest category as of 2020, having grown from 1.6 billion in 2010 to 1.9 billion in 2020 (a 17% increase).
Religion in America (2024)
According to the 2024 PRRI Census of American Religion and the Pew Research Center’s 2023–24 Religious Landscape Study, approximately 65% of Americans identify as Christian. The religiously unaffiliated population reached a new peak of 28% in 2024. Non-Christian faith traditions collectively represent approximately 6–7% of Americans.
U.S. total population baseline: approximately 335 million.
Christianity
Global Profile
Christianity is the world’s largest religion, with approximately 2.3 billion adherents representing just under 29% of the global population as of 2020. The Catholic Church alone claims approximately 1.36 billion members, or roughly half of all Christians. Evangelical Christians number approximately 619 million globally. The Christian population grew by 122 million between 2010 and 2020, though Islam grew faster in raw numbers over the same period.
Nearly 87% of all Christians live in Christian-majority countries, of which there are 157. Christianity is particularly dominant in Latin America, sub-Saharan Africa, North America, and Europe.
In America
The United States has the world’s single largest Christian population by country — approximately 217 million, or 64% of the population. This includes roughly 40% Protestant, 19% Catholic, and 3% other Christian denominations. White evangelical Protestants represent about 23% of all U.S. adults, down from 26% in 2007.
Major Christian-Majority Countries
Islam
Global Profile
Islam is the world’s second-largest religion and fastest-growing major faith, with approximately 2 billion adherents (25.6% of global population) as of 2020. Muslim population grew by 327 million between 2010 and 2020 — more than all other religions combined. Sunni Muslims constitute 87–90% of all Muslims; Shia Muslims account for 10–13%. There are 50 Muslim-majority countries worldwide.
In America
There are approximately 4 million Muslims in the United States, representing about 1.2% of the U.S. population. This makes Islam one of the fastest-growing religious minorities in America, primarily through immigration and conversion.
Percentage of Americans who are Muslim: ~1.2%
Major Muslim-Majority Countries and % Christian
Note: Egypt’s Coptic Christian community — estimated at 10–15 million — is the single largest Christian community in the entire Middle East. Indonesia, despite being the world’s most populous Muslim nation, has the second-largest Christian population in the Muslim world after Nigeria. Saudi Arabia has approximately 1.5–2 million Christians, but all are foreign workers; no Saudi citizens are officially permitted to identify as Christian.
Hinduism
Global Profile
Hinduism is the world’s third-largest religion, with approximately 1.16–1.2 billion adherents, representing 14.9% of global population. It is the world’s oldest living major religion, dating back more than 4,000 years. Notably, 94% of all Hindus in the world live in India, and 97% of all Hindus worldwide live in just three Hindu-majority countries: India, Nepal, and Mauritius.
In America
There are approximately 3 million Hindus in the United States, representing about 0.9% of the population. This community is primarily composed of immigrants from India and their descendants.
Percentage of Americans who are Hindu: ~0.9%
Major Hindu-Majority Countries and % Christian
Note: Sri Lanka, while not Hindu-majority (it is 70% Buddhist), has a significant Hindu minority of approximately 12%. Christians in Sri Lanka represent approximately 9% of the population. India’s Christian community of approximately 30–33 million is one of the largest in Asia, concentrated primarily in the southern states and northeast, yet constitutes only 2.3–2.4% of a population exceeding 1.4 billion.
Buddhism
Global Profile
Buddhism is the world’s fourth-largest religion with approximately 506–510 million adherents, representing 4.1% of global population as of 2020. It is notable as the only major religion that actually declined in total numbers between 2010 and 2020, primarily due to religious disaffiliation in East Asia and low birth rates. Buddhism is the state religion in four countries: Cambodia, Myanmar, Bhutan, and Sri Lanka. The religion is concentrated overwhelmingly in Southeast Asia, East Asia, and South Asia.
In America
There are approximately 3.5–4 million Buddhists in the United States, representing about 1.1% of the population. The American Buddhist community includes both Asian-American immigrants and converts of non-Asian heritage.
Percentage of Americans who are Buddhist: ~1.1%
Major Buddhist-Majority Countries and % Christian
Note: Japan presents a unique case in which Shinto (70.5%) and Buddhism (67.2%) have historically been practiced simultaneously by the same individuals, making single-religion percentages misleading. The country’s constitution guarantees freedom of religion, and approximately 1–2% of Japanese identify as Christian. In China, the government officially recognizes Buddhism among five permitted religions, but estimates of Christian adherents range widely from 2% to 6% depending on methodology, with the official Pew figure at approximately 2% (about 28 million people).
Judaism
Global Profile
Judaism is one of the world’s oldest monotheistic religions, with approximately 15.7–17.1 million adherents worldwide, representing less than 0.2% of the global population. The Jewish world population suffered catastrophic losses during the Holocaust and has never fully recovered in proportional terms. As of January 2024, the world’s Jewish population was estimated at approximately 15.7 million. Growth is almost entirely concentrated in Israel.
In America
The United States is home to the world’s second-largest Jewish population — approximately 6.3 million by core identification, a figure representing roughly 36.8% of all Jews worldwide. Israel hosts approximately 7.15 million. The American Jewish community is heavily concentrated in New York, California, Florida, and New Jersey.
Percentage of Americans who are Jewish: ~1.7–2%
Major Countries by Jewish Population
Note: Israel is the only country in the world where Jews constitute a majority of the population (~75%). Christians in Israel represent approximately 2% of the population, primarily Arab Christians. Judaism is not a proselytizing religion and has no significant missionary activity, which partly explains why Jewish populations remain small despite the faith’s extraordinary historical and cultural influence.
Sikhism
Global Profile
Sikhism is a monotheistic religion founded in the 15th century by Guru Nanak in Punjab, India. It is often cited as the world’s fifth-largest organized religion, with approximately 25–30 million adherents worldwide. Approximately 90–95% of all Sikhs live in India, with the great majority concentrated in the state of Punjab, the world’s only Sikh-majority administrative division. Sikh populations also exist in Canada, the United Kingdom, the United States, Italy, and Australia.
In America
There are approximately 280,000 to 500,000 Sikhs in the United States, representing approximately 0.1% of the U.S. population. The American Sikh community is concentrated in California, New York, Texas, Michigan, and New Jersey. Sikhism’s lack of a missionary tradition and relatively small global population base limit its growth in America compared to other immigrant faiths.
Percentage of Americans who are Sikh: ~0.1%
Countries with Significant Sikh Populations
Punjab, India is 58% Sikh and represents the heartland of the Sikh faith and culture. Christians in Punjab represent approximately 1.26% of the population.
The Religiously Unaffiliated (Atheists, Agnostics, and “Nones”)
Global Profile
The religiously unaffiliated population — encompassing atheists, agnostics, and those who identify with no organized religion — is the world’s third-largest religious category with approximately 1.9 billion people, representing 24.2% of global population as of 2020. This category grew by 17% between 2010 and 2020. However, because the unaffiliated are concentrated in low-fertility regions (primarily East Asia and Europe) and not organized around a shared theology or community, Pew projects that their global share will actually decline by 2050 even as absolute numbers grow.
Importantly, a large proportion of the “unaffiliated” still hold some religious or spiritual beliefs. Among unaffiliated Americans, 68% believe in God or a higher power. About 18% of self-described atheists believe in some kind of higher power.
In America
In 2024, approximately 28–29% of Americans identify as religiously unaffiliated, reaching a new peak. This includes:
Percentage of Americans who are atheist: ~3–4%
Percentage of Americans who are religiously unaffiliated (all “nones”): ~28–29%
Countries with Highest Non-Religious Populations
Note: China is the world’s largest unaffiliated population by count — approximately 1.3 billion adults report no religious affiliation in some surveys. The Chinese government officially promotes atheism while permitting the practice of five state-recognized religions (Buddhism, Taoism, Islam, and two forms of Christianity). Christians in China are estimated at 2–5% of the population (approximately 28–49 million people), with the higher figures including underground house church members.
Christians as a Minority: Presence Across Non-Christian Nations
One striking dimension of global Christianity is how many millions of Christians live as minorities within non-Christian-majority societies. The table below summarizes the Christian percentage across major non-Christian-majority countries:
Christians in Muslim-Majority Nations
Christians in Hindu-Majority Nations
Christians in Buddhist-Majority Nations
Christians in Largely Secular / Unaffiliated Nations
Key Takeaways
Christianity is uniquely global. No other religion approaches the geographic spread of Christianity, which claims a substantial presence on every continent and in 157 majority nations. With 217 million adherents, America hosts the largest national Christian population in the world.
Islam is growing fastest. Muslim population grew by 327 million between 2010 and 2020 — more than all other religions combined. By 2050, Islam is projected to approach Christianity in total global adherents.
Hinduism and Buddhism are geographically concentrated. Over 94% of Hindus live in India, and the Buddhist heartland is concentrated in Southeast and East Asia. Both religions have smaller diaspora footprints in America compared to Christianity, Islam, or Judaism.
The unaffiliated are America’s second-largest “group.” At 28–29%, the religiously unaffiliated are now America’s second-largest religious category after Christianity — larger than any individual non-Christian faith by a very wide margin. Committed atheists remain at approximately 3–4% of the U.S. population.
Christians persist as minorities in non-Christian nations. Significant Christian populations exist across Muslim-majority, Hindu-majority, and Buddhist-majority countries — from Egypt’s 10–15 million Coptic Christians, to India’s 30+ million Christians, to Indonesia’s 40 million Christians (approximately 15% of population). These communities often practice their faith in environments that range from fully free to actively repressive.
Judaism punches far above its weight. With fewer than 17 million adherents worldwide — less than 0.2% of humanity — Judaism’s global cultural, theological, and political influence far exceeds its numbers, a testament to its ancient history and the disproportionate concentration of the global Jewish population in two highly influential nations: Israel and the United States.
Data primarily sourced from Pew Research Center’s 2025 “How the Global Religious Landscape Changed from 2010 to 2020” study, the 2024 PRRI Census of American Religion, the Pew 2023–24 Religious Landscape Study, the World Population Review, and the Jewish Virtual Library’s World Jewish Population 2024 report.