World Religions by Number of Followers: Statistics and Sources

How many Christians, Muslims, Hindus, Buddhists, Jews and people of no religion there are in the world and in the United States, how those numbers changed from 2010 to 2020, and where they are heading: the latest figures from Pew Research Center, the Center for the Study of Global Christianity and the U.S. Religion Census, every number linked to the report it comes from.

By the editors of Weekday GraceUpdated October 202661 statistics, no ads, no sign-up

World religions by number of followers

Pew Research Center’s 2025 report is the most recent full count of the world’s religions. It sorts everyone into seven groups using more than 2,700 censuses and surveys from 201 countries and territories, and it counts people by the religion they say they belong to.

1. 2.3B

   Christians numbered 2.3 billion in 2020, up 122 million since 2010, and remained the world’s largest religious group.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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2. 28.8%

   Christians made up 28.8% of the world’s population in 2020, down 1.8 percentage points since 2010, because their numbers grew more slowly than the world’s population.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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3. 2.0B

   Muslims numbered 2.0 billion in 2020. Their number grew by 347 million from 2010, more than all other religions combined.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1] [2]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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4. 25.6%

   Muslims made up 25.6% of the world’s population in 2020, up 1.8 percentage points since 2010, the fastest growth of any major group.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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5. 1.9B

   1.9 billion people had no religious affiliation in 2020, up 270 million since 2010. They are the third-largest group, after Christians and Muslims.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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6. 24.2%

   24.2% of the world’s people did not identify with any religion in 2020, up from 23.3% in 2010; 75.8% identified with a religion.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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7. 1.2B

   Hindus numbered 1.2 billion in 2020, up 126 million since 2010, and held steady at 14.9% of the world’s population.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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8. 324M

   Buddhists numbered 324 million in 2020, down 19 million since 2010, and fell to 4.1% of the world’s population. They were the only major group to shrink in number.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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9. 14.8M

   Jews numbered 14.8 million in 2020, up by nearly 1 million since 2010, about 0.2% of the world’s population.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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10. 2.2%

    All other religions combined, including Baha’is, Daoists, Jains, Sikhs and followers of folk religions, held steady at 2.2% of the world’s population, growing from 154 million to 172 million people.

    Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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Growth and change, 2010 to 2020

Most religious groups grew in number over the decade because the world’s population grew. What changed their shares was age, birth rates and religious switching: Muslims are the youngest group, while many people raised Christian, and some raised Buddhist, now say they have no religion.

1. 3.1 : 1

   Christians had the largest net losses from religious switching: for every 1 person who became Christian, 3.1 people raised Christian left (adults 18 to 54). Most who left now have no religion.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2010-2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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2. 120

   Christians were a majority in 120 countries and territories in 2020, down from 124 in 2010. They fell below half the population in the United Kingdom (49%), Australia (47%), France (46%) and Uruguay (44%).

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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3. 10

   People with no religion became a majority in the Netherlands (54%), Uruguay (52%) and New Zealand (51%), raising the number of places with an unaffiliated majority from 7 to 10.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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4. 1.3B

   China’s 1.3 billion religiously unaffiliated people made up 90% of its population in 2020, about two-thirds of all the unaffiliated people in the world.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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5. 95%

   About 95% of the world’s Hindus live in India, and 99% live in the Asia-Pacific region.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020: Hindus (June 9, 2025) [3]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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6. 85%

   85% of the world’s Jews live in Israel or the United States. Nearly half live in Israel, the only country where Jews are more than 2% of the population.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020: Jews (June 9, 2025) [4]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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7. 64.0%

   Counting people of all ages, the Christian share of the U.S. population fell from 78.3% in 2010 to 64.0% in 2020, while the unaffiliated share rose from 16.5% to 29.7%.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2010-2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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Projections

Pew’s projections were published in 2015 and start from its earlier 2010 estimates, which it has since revised (see How religions are counted). They show what would happen if the trends of that time continued; they are not predictions.

1. 2.9B / 2.8B

   If 2015 trends held, by 2050 there would be near parity between Christians (2.9 billion, 31% of the world) and Muslims (2.8 billion, 30%).

   Pew Research Center, The Future of World Religions: Population Growth Projections, 2010-2050 (April 2, 2015) [5]Data: projection to 2050Pew projections from 2010 baseline data for 198 countries and territories

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2. 73%

   Muslims were projected to grow 73% between 2010 and 2050, against 35% for the world’s population and about 35% for Christians.

   Pew Research Center, The Future of World Religions: Population Growth Projections, 2010-2050 (April 2, 2015) [5]Data: projection to 2050Pew projections from 2010 baseline data for 198 countries and territories

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3. ~2070

   Extended past 2050, the projection has Muslims and Christians at roughly 32% each around 2070, and Muslims at 35% vs. Christians at 34% by 2100.

   Pew Research Center, The Future of World Religions: Population Growth Projections, 2010-2050 (April 2, 2015) [5]Data: projection to 2100Pew projections from 2010 baseline data for 198 countries and territories

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4. 38%

   Sub-Saharan Africa’s Christian population was projected to double from 517 million in 2010 to 1.1 billion in 2050, rising from 24% to 38% of the world’s Christians.

   Pew Research Center, The Future of World Religions: Population Growth Projections, 2010-2050 (April 2, 2015) [5]Data: projection to 2050Pew projections from 2010 baseline data for 198 countries and territories

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5. 66%

   For the United States, the 2015 projections had Christians falling from 78% of the population in 2010 to 66% in 2050, and the unaffiliated rising from 16% to 26%.

   Pew Research Center, The Future of World Religions: Population Growth Projections, 2010-2050 (April 2, 2015) [5]Data: projection to 2050Pew projections from 2010 baseline data for 198 countries and territories

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6. 16% → 13%

   The 2015 projections, using the older 2010 baseline, had the unaffiliated falling from 16% of the world in 2010 to 13% in 2050. Pew’s 2025 report revised the 2010 figure to 23.3% (see below).

   Pew Research Center, The Future of World Religions: Population Growth Projections, 2010-2050 (April 2, 2015) [5] [1]Data: projection to 2050Pew projections from 2010 baseline data for 198 countries and territories

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Christianity by tradition and region

…a great multitude that no one could number, from every nation, from all tribes and peoples and languages…

Revelation 7:9 (ESV)

Two research centers publish worldwide counts of Christians by tradition, and their totals differ: about 2.3 billion Christians in 2020 by Pew’s count, and 2.6 billion in 2025 by the other center’s. Pew counts people who call themselves Christian in censuses and surveys. The Center for the Study of Global Christianity at Gordon-Conwell Theological Seminary also uses church membership records and counts “unaffiliated” Christians who belong to no church. Both are shown, with the year each describes.

The two columns describe different years and use different categories, so compare each one with itself over time rather than with the other. The tradition breakdown in the Pew column comes from its 2011 study; its 2025 report counts Christians of all denominations as one group.

1. 30.7%

   Sub-Saharan Africa is now home to more Christians than any other region: 30.7% of the world’s Christians in 2020, compared with 22.3% in Europe.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025) [1]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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2. 697M

   Christians in sub-Saharan Africa grew 31% to 697 million between 2010 and 2020, while their numbers fell in Europe (to 505 million, down 9%) and North America (to 238 million, down 11%).

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020: Christians (June 9, 2025) [6]Data: 2020Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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3. 50 / 37 / 12%

   In Pew’s 2010 count, about half of the world’s Christians were Catholic (50%), 37% Protestant (broadly defined), 12% Orthodox and 1% other Christians such as Latter-day Saints and Jehovah’s Witnesses.

   Pew Research Center, Global Christianity: Christian Traditions (December 19, 2011) [7] [8]Data: 2010Pew analysis of 2010 data for more than 200 countries

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4. 1.1B

   Pew counted 1.1 billion Catholics in 2010; Brazil had the most (134 million).

   Pew Research Center, Global Christianity: Christian Traditions (December 19, 2011) [7] [8]Data: 2010Pew analysis of 2010 data for more than 200 countries

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5. 801M

   Pew counted 801 million Protestants, broadly defined, in 2010. More lived in sub-Saharan Africa (37%) and the Americas (33%) than in Europe (13%).

   Pew Research Center, Global Christianity: Christian Traditions (December 19, 2011) [7] [8]Data: 2010Pew analysis of 2010 data for more than 200 countries

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6. 260M

   Pew counted about 260 million Orthodox Christians in 2010; 39% of them lived in Russia and 77% in Europe.

   Pew Research Center, Global Christianity: Christian Traditions (December 19, 2011) [7] [8]Data: 2010Pew analysis of 2010 data for more than 200 countries

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7. 2.65B

   The Center for the Study of Global Christianity estimates 2,645,317,000 Christians in 2025, 32.3% of the world, using a wider definition than Pew (see Why the counts differ).

   Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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8. 1.27B

   Catholics: 1,272,775,000 in 2025 (Center for the Study of Global Christianity).

   Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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9. 629M

   Protestants, including Anglicans: 628,862,000 in 2025.

   Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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10. 409M

    Independents, members of churches outside the historic denominations: 409,425,000 in 2025, up from 8,859,000 in 1900.

    Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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11. 292M

    Orthodox Christians: 291,580,000 in 2025.

    Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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12. 664M

    Pentecostals and Charismatics, counted across all traditions: 663,863,000 in 2025, projected at 1,031,503,000 by 2050.

    Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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13. 68.9%

    68.9% of the world’s Christians lived in the Global South in 2025, up from 17.6% in 1900; the Center projects 78.0% by 2050.

    Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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14. 754M

    Africa had 754,229,000 Christians in 2025, more than Latin America (620,116,000) or Europe including Russia (551,934,000).

    Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary, Status of Global Christianity, 2025, in the Context of 1900-2050 [9]Data: 2025 (estimate)World Christian Database estimates (Brill, accessed January 2025)

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15. 1.41B

    The Vatican’s own records count 1,405,454,000 baptized Catholics as of June 30, 2023, 17.8% of the world’s population.

    Agenzia Fides (Vatican), Catholic Church Statistics 2025 (October 2025) [10]Data: 2023Vatican Statistical Yearbook of the Church

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Religion in the United States

Pew’s Religious Landscape Study surveyed 36,908 adults in 2023-24, large enough to measure small groups and individual denominations. Gallup asks a shorter religion question in every monthly poll, so it reports a yearly number. The two use different questions and methods, which is why their figures differ by a few points.

• Protestant 40%
• Catholic 19%
• Other Christian 3%
• Other religions 7%
• Unaffiliated 29%

1. 62%

   62% of U.S. adults describe themselves as Christians: 40% Protestant, 19% Catholic and 3% other Christians.

   Pew Research Center, Religious Landscape Study: Executive Summary (February 26, 2025) [11]Data: 2023-2436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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2. 78 → 62%

   The Christian share of U.S. adults fell from 78% in 2007 to 71% in 2014 and 62% in 2023-24. Pew finds the decline has slowed and may have leveled off since about 2019.

   Pew Research Center, Religious Landscape Study: Religious Identity (February 26, 2025) [12] [11]Data: 2007-202436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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3. 29%

   29% of U.S. adults are religiously unaffiliated: 5% atheist, 6% agnostic and 19% ‘nothing in particular.’

   Pew Research Center, Religious Landscape Study: Executive Summary (February 26, 2025) [11]Data: 2023-2436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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4. 7%

   7% of U.S. adults belong to religions other than Christianity: 2% are Jewish, and about 1% each are Muslim, Buddhist or Hindu.

   Pew Research Center, Religious Landscape Study: Executive Summary (February 26, 2025) [11]Data: 2023-2436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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5. 23 / 11 / 5%

   Evangelical Protestants make up 23% of U.S. adults (26% in 2007), mainline Protestants 11% (18%), and the historically Black Protestant tradition 5% (7%).

   Pew Research Center, Religious Landscape Study: Executive Summary (February 26, 2025) [11]Data: 2023-2436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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6. 19%

   Catholics are 19% of U.S. adults, down from 24% in 2007; the share has ranged between 18% and 21% in Pew surveys since 2014.

   Pew Research Center, Religious Landscape Study: Religious Identity (February 26, 2025) [12]Data: 2023-2436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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7. 12% / 7%

   Baptists are the largest Protestant family, 12% of U.S. adults. Nondenominational Protestants are second at 7%, the only Protestant family larger than in 2007.

   Pew Research Center, Religious Landscape Study: Religious Identity (February 26, 2025) [12]Data: 2023-2436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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8. 35%

   35% of U.S. adults have switched religions since childhood, with net gains for the unaffiliated and net losses for Christians.

   Pew Research Center, Religious Landscape Study: Executive Summary (February 26, 2025) [11]Data: 2023-2436,908 U.S. adults, July 17, 2023-March 4, 2024, mostly online and by mail

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9. 24%

   In Gallup’s 2025 surveys, 24% of Americans reported no religion, a new high; 44% identified as Protestant or nondenominational Christian, 20% as Catholic and 9% as another religion.

   Gallup, Americans’ Religious Engagement Holds at Lower Levels (March 3, 2026) [13]Data: 2025Gallup monthly telephone surveys in 2025, combined 13,454 U.S. adults

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U.S. congregations by tradition

The U.S. Religion Census takes a different approach: instead of asking individuals, it asks religious bodies how many congregations and adherents they have in every county. It has been taken every ten years since 1952, now by the Association of Statisticians of American Religious Bodies, and its data are archived at the Association of Religion Data Archives (ARDA).

1. 356,642

   The 2020 U.S. Religion Census counted 356,642 congregations in 3,141 of the country’s 3,143 counties.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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2. 161.2M

   Those congregations reported 161,224,088 adherents, 48.6% of the 2020 U.S. population. Surveys find more people identify with a religion than belong to a congregation.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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3. 61.9M

   Catholic: 19,522 congregations with 61,858,937 adherents, 18.7% of the population and the largest tradition by adherents.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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4. 199,694

   Conservative (evangelical) Protestant: 199,694 congregations, more than half of all U.S. congregations, with 54,652,238 adherents.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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5. 69,865

   Mainline Protestant: 69,865 congregations with 17,184,424 adherents.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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6. 23,483

   Black Protestant: 23,483 congregations with 7,404,653 adherents (the census notes these bodies are harder to count and estimates some of them).

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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7. 51,379

   The Southern Baptist Convention has more congregations than any other U.S. body: 51,379, with 17,649,040 adherents.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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8. 44,319

   Non-denominational Christian churches: 44,319 congregations with 21,095,641 adherents, the second-largest group by adherents after the Catholic Church.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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9. 14,631

   Latter-day Saints: 14,631 congregations with 6,721,031 adherents. Jehovah’s Witnesses: 12,285 congregations with 3,016,924 adherents.

   Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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10. 2,771

    Islam: 2,771 mosques with 4,453,908 adherents, nearly 700 more mosques than in 2010.

    Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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11. 3,306

    Judaism: 3,306 congregations with 2,068,827 adherents. The census notes that surveys estimate 7.5 million Jews in the U.S., far more than belong to a congregation.

    Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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12. 1,811 / 1,984

    Hinduism: 1,811 congregations with 1,268,344 adherents. Buddhism: 1,984 congregations with 1,040,796 adherents.

    Association of Statisticians of American Religious Bodies (ASARB), 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023) [14]Data: 2020Counts reported by or for 372 religious bodies

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How religions are counted, and why sources differ

For years, many library guides and classroom pages pointed to Adherents.com, an independent index that gathered membership figures for religious groups around the world from many published sources. That site is no longer online. Its lesson still holds: a religion’s size depends on who is counting and how. Four kinds of count appear on this page.

Self-identification

People say which religion they belong to in a census or survey. Pew Research Center and Gallup count this way. It includes people who rarely or never attend services.

Affiliation and professing

The Center for the Study of Global Christianity combines censuses and surveys with church membership records, and also counts “unaffiliated” Christians who profess the faith but belong to no church. This gives higher totals than Pew.

Church records

Some churches count their own members. The Catholic Church counts baptized Catholics, so the Vatican’s total of 1.41 billion can include baptized people who would not describe themselves as Catholic in a survey.

Congregational adherents

The U.S. Religion Census counts people connected to a congregation, as reported by each religious body. Its 161 million adherents equal 48.6% of the population, well below the share of Americans who tell surveys they have a religion.

Why the 2010 numbers changed

Estimates are revised as methods and data improve. In 2025, Pew changed how it counts religion in China, which holds a large share of the world’s people, so that it uses the same single identity question it uses elsewhere. That change is the main reason its estimate of the world’s unaffiliated people in 2010 rose from 16% (in its 2015 projections) to 23.3% (in its 2025 report), and its estimate of Buddhists fell.

1. 52% → 87%

   Pew revised its 2010 estimate of Chinese people with no religious affiliation from 52% to 87% by switching to a single question about religious identity, the method it uses in other countries.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020: Why we revised our estimates for 2010 (June 9, 2025) [15]Data: 2010 (revised 2025)Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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2. 7% → 5%

   The same revision lowered Buddhists’ share of the 2010 world population from 7% to 5%, the largest downward change for any group.

   Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020: Why we revised our estimates for 2010 (June 9, 2025) [15]Data: 2010 (revised 2025)Pew analysis of more than 2,700 censuses and surveys for 201 countries and territories

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Comparing sources fairly

Compare like with like: the same source, the same definition and, where possible, the same year. A survey of adults is not the same as a count of people of all ages (Pew’s 64% Christian figure for the U.S. includes children; its 62% is adults only). A Jewish population counted by religion (5.7 million Americans in Pew’s 2025 report) is smaller than one that includes people who are Jewish by culture or family background (7.5 million). Where two good sources disagree on this page, both are shown and the reason is given.

For teachers and librarians

Sources

1. Pew Research Center. How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025)
2. Pew Research Center. How the Global Religious Landscape Changed From 2010 to 2020: Muslims (June 9, 2025)
3. Pew Research Center. How the Global Religious Landscape Changed From 2010 to 2020: Hindus (June 9, 2025)
4. Pew Research Center. How the Global Religious Landscape Changed From 2010 to 2020: Jews (June 9, 2025)
5. Pew Research Center. The Future of World Religions: Population Growth Projections, 2010-2050 (April 2, 2015)
6. Pew Research Center. How the Global Religious Landscape Changed From 2010 to 2020: Christians (June 9, 2025)
7. Pew Research Center. Global Christianity: Christian Traditions (December 19, 2011)
8. Pew Research Center. Global Christianity: Executive Summary (December 19, 2011)
9. Center for the Study of Global Christianity, Gordon-Conwell Theological Seminary. Status of Global Christianity, 2025, in the Context of 1900-2050
10. Agenzia Fides (Vatican). Catholic Church Statistics 2025 (October 2025)
11. Pew Research Center. Religious Landscape Study: Executive Summary (February 26, 2025)
12. Pew Research Center. Religious Landscape Study: Religious Identity (February 26, 2025)
13. Gallup. Americans' Religious Engagement Holds at Lower Levels (March 3, 2026)
14. Association of Statisticians of American Religious Bodies (ASARB). 2020 U.S. Religion Census: Religious Congregations & Adherents Study (2023)
15. Pew Research Center. How the Global Religious Landscape Changed From 2010 to 2020: Why we revised our estimates for 2010 (June 9, 2025)