The world’s religious makeup is shifting as global population growth, migration and religious switching reshape the landscape, according to a new report by the Pew Research Centre.
The study, based on more than 2,700 censuses and surveys, shows that while Christians remain the world’s largest religious group, their share of the global population has declined. In 2020, 2.3 billion people identified as Christian, but as a percentage of the global population, this represents 28.8%, down from 30.6% a decade earlier.
Meanwhile, Muslims were the fastest-growing major religious group, with their numbers increasing by 347 million to reach 2.0 billion, or 25.6% of the global population. This marks a 1.8 percentage point rise in the Muslim share of the population since 2010.
The number of people with no religious affiliation, sometimes called “nones”, also grew significantly. The unaffiliated now account for 1.9 billion people, or 24.2% of the world’s population — up nearly a percentage point from 2010.
Hindus, whose growth rate has roughly matched global population growth, held steady at 14.9%, with 1.2 billion adherents.
Buddhists were the only major religious group to shrink in absolute numbers, declining by 19 million to 324 million, or 4.1% of the global population.
The Jewish population saw a slight increase to 14.8 million, maintaining their share of 0.2%. Other religions, including Sikhism, Baha’i, Jainism, Daoism, folk religions and others, also grew in line with global population growth and now represent 2.2% of the world’s people.
The report highlights two key trends driving these changes: natural population growth — especially among Muslims, who tend to have younger populations and higher fertility rates — and religious switching, particularly in the Americas, Europe and Australia, where many are disaffiliating from Christianity.
In Australia, for example, the share of Christians fell by 20 percentage points between 2010 and 2020, while the religiously unaffiliated population grew by 17 percentage points, part of a wider global trend in developed nations.
Sub-Saharan Africa has emerged as a significant centre of Christian growth, now home to 30.7% of the world’s Christians, surpassing Europe for the first time.
The Pew Research Centre report underscores that the future religious landscape will continue to be shaped by factors such as fertility rates, religious switching, migration and population ageing, with the full impact of these trends likely to unfold in the decades ahead.
The study is part of the Pew-Templeton Global Religious Futures project, which tracks religious change worldwide and its implications for societies.
Source: Pew Research Centre, How the Global Religious Landscape Changed From 2010 to 2020, 9 June 2025.
