Islam Is World’s Fastest-Growing Religion

Islam grew faster than any other major religious group globally from 2010 to 2020, according to estimates released on Monday from Pew Research Center, a U.S.-based think tank.

Over the period, the number of Muslims worldwide increased by 347 million compared to 122 million for Christians, with the share of the world’s population that is Christian actually falling, as the gains failed to keep up with population growth. The second biggest rise was recorded by the religiously unaffiliated.

Why It Matters

The rapid growth of Islam reflects significant demographic shifts that are altering the global religious landscape. For Americans, understanding these trends is vital as they influence migration, international relations and social dynamics both domestically and abroad. Experts found that higher birth rates and a younger median age among Muslims drove much of this surge, helping narrow the gap between Muslims and Christians worldwide.

What To Know

The Pew Research Center data from the time frame showed the number of Muslims globally reaching around 2 billion, as the proportion of the world’s population that was Muslim rose from 23.9 percent to 25.6 percent.

Over the same time, Christians’ share of the global population fell from 30.6 percent to 28.8 percent.

After Islam the biggest gains were recorded by the religiously unaffiliated, which saw their total increase by 300 million to 1.9 billion, representing 24.2 percent of the global population. This was a 0.9 percent increase in their share of the global population.

Out of the religions surveyed, only Buddhism saw its number of global adherents fall in absolute terms, by 19 million, to 324 million people.

Pew analyzed data from more than 2,700 sources spanning national censuses, demographic surveys and population registers. The study covered 201 countries or territories, accounting for nearly the entire world population.

Separately, data from Pew’s Religious Landscape Study found the number of religiously unaffiliated increased from 2007, or in some cases 2014, and 2023-24 in every U.S. state except South Dakota.

Higher Birthrates

The study found that birthrates were the main cause of the growing Muslim population, with the number of conversions to Islam roughly offset by the number of people leaving the religion.

Muslim women had, on average, 2.9 children in their lifetime from 2015 to 2020, compared to 2.2 children for non-Muslim women.

Conversion played a negligible role in Muslim population growth, with about 1 percent of those raised Muslim leaving the faith, offset by a similar number joining Islam. Growth stemmed nearly entirely from natural demographic trends.

The median age for Muslims in 2020 was 24, which is nine years younger than the median for non-Muslims, suggesting the Muslim share of the global population will continue to increase.

Global Distribution

In 2020, the largest Muslim populations were in the Asia-Pacific region (1.2 billion), with smaller but quickly growing populations in the Middle East-North Africa (414 million) and sub-Saharan Africa (369 million). Countries with the most Muslims included Indonesia, Pakistan, India and Bangladesh. Islam formed a majority in 53 countries or territories worldwide.

What People Are Saying

Speaking to Newsweek, Professor Faisal Devji, expert in Islam at the University of Oxford, said: “Having just read the report, I see that the increase in Muslim population is largely natural, due to younger populations and so higher birthrates in Sub-Saharan Africa and the Middle East, rather than due to any change in religious affiliation. In fact it appears that the real story here is the spectacular rise of disaffiliated or non-religious people globally, but especially in wealthy countries. At more than 24% of the global population they seem to point to the decline of formal religion as such. What we need to attend to in Islam, therefore, is not its growth so much as resilience for the time being.”

Professor Rumee Ahmed, expert in Islamic law at University of British Columbia, told Newsweek: “The biggest demographic story of the last decade has been sub-Saharan Africa, where the population grew by more than 70% from 2010-2020 due largely to improved health outcomes and infant mortality, and for the first time there are more Christians in sub-Saharan Africa than there are in Europe. About a third of this population is Muslim, and that coupled with a steady 15-20% population growth in Muslim-dense areas like South Asia and South-East Asia accounts for most of the growth in the Muslim population.

“In many of these areas, religion is a state-defined identity marker and, unlike in most Western countries, citizens are asked to affiliate with one religious group and are registered with the state as such, with rights and responsibilities that go along with that identity. This is part of a legacy that goes back to the colonial period; the data tell us nothing about religiosity, beliefs, and practices, just how respondents identify.”

Ibrahim Hooper, communications director of the Council on American-Islamic Relations (CAIR) said: “As to the growth of the Muslim community in the United States, we have previously noted that the increase is due to a number of factors, including conversion, a higher-than-average birth rate and immigration from Muslim-majority areas.”

Andrew Copson, president of Humanists International, a group which promotes secularism, commented: “All over the world people are finding that religious beliefs no longer offer them good guidance on morality, meaning in life, or effective ways to understand the universe. The rising number of people declaring themselves proudly not to be religious is a natural consequence of all of this.”

Melina Cohen, director of strategic communications and policy engagement at American Atheists, told Newsweek: “The Nones are not a monolith, and people are religiously unaffiliated for a number of reasons. Some never left religion but were raised secularly. Others leave after experiencing religious trauma and abuse. Many more are disturbed by the politicization of churches and turned off by dogmas that promote hate and discord, finding religious teachings and traditions to be outdated and incompatible with their values.”

What Happens Next

The Pew center projects these demographic trends will continue over coming decades, potentially changing the relative sizes of global religious populations by midcentury.