☸ 5th-century BCE Ganges plain
Buddhism
The only major religion that shrank in absolute numbers between 2010 and 2020.
Adherents
324m
Share of world
4.1%
Median age
35
Net from switching
-29m
Where it is actually moving
Sharp net losses in Japan, South Korea and urban China, where large shares of people raised Buddhist now identify with no religion.
Largest Buddhist populations
China
169m · 12%China holds the largest unaffiliated population on Earth — roughly 875 million people — alongside one of the fastest-growing Protestant communities.
Thailand
66.2m · 92%One of the most religiously stable countries measured: 98% of adults raised Buddhist in Thailand remain Buddhist.
Japan
39.7m · 32%Most Japanese take part in Shinto and Buddhist ritual while reporting no religious affiliation — the clearest case anywhere of practice without belonging.
Vietnam
15.8m · 16%Protestant Christianity has grown fastest among the Hmong of the northern highlands, from almost nothing in 1985 to several hundred thousand.
India
14.3m · 1%Pew's landmark India survey found 98% of Indian adults still identify with the religion they were raised in — the lowest switching rate of any large country on Earth.
South Korea
8.3m · 16%South Korea went from 1% Christian in 1900 to about a third today, and is now secularising faster than almost any country in Asia.
United States
3.4m · 1%For every American raised with no religion who has since joined one, about six raised Christian have left — the largest raw switching flow in the Western hemisphere.
Nepal
2.8m · 9%Nepal's Christian population has grown from a few hundred people in 1951 to over half a million — proportionally one of the fastest conversions to Christianity anywhere.
Indonesia
2.8m · 1%The world's largest Muslim-majority country also contains Bali, a Hindu island of over 4 million within an 87% Muslim nation.
Bangladesh
1.7m · 1%The Hindu share has fallen from about 22% at independence in 1971 to under 9%, driven by migration rather than conversion.
Australia
0.5m · 2%'No religion' overtook Christianity in the 2021 census; Hinduism and Sikhism are the country's fastest-growing faiths, driven by migration.
Canada
0.4m · 1%Canada's Sikh population has more than doubled since 2001 and now exceeds 770,000, the largest share of any country outside India.