A new report from the Pew Research Center reveals that Islam is growing significantly faster than any other religion in the world. Between 2010 and 2020, the number of Muslims increased by a staggering 347 million people, more than the combined growth of all other major religions, and nearly three times the growth of Christianity during the same period. This surge is fueled by high birth rates, a youth-dominated age structure, and mass migration, particularly into Western nations.
According to Pew, Islam’s global population grew from 1.6 billion in 2010 to approximately 1.94 billion by 2020, raising the Muslim share of the world’s population from 23.8% to 25.6%. This makes Islam not only the fastest-growing major religion but the only one increasing its global share in nearly every region.
Two Main Drivers: High Fertility and Youth-Dominated Demographics
Pew identifies natural population growth, more births than deaths, as the primary factor behind Islam’s global expansion. Muslim populations have the highest fertility rate of any major religious group: 2.9 children per woman globally, well above the replacement rate of 2.1 and higher than the Christian average of 2.6.
Islam also has a uniquely young age profile: 33% of the global Muslim population is under the age of 15, compared to 27% of Christians and 19% of the religiously unaffiliated. The median age of Muslims globally is 24, the youngest of any religious group, guaranteeing decades of continued growth.
Migration Expands Islam’s Reach in the West
While global Muslim growth is driven primarily by births, migration plays a powerful role regionally, especially in Europe and North America. Pew projects that the Muslim population in Europe could reach 14% or more by 2050, depending on immigration levels. In the United States, the Muslim population is projected to double between 2010 and 2050, and surpass Jews as the second-largest religious group by mid-century.
Although migration does not affect global totals, it is dramatically reshaping the religious landscape of Western countries where Muslim migrants are concentrated.
Christianity: Still the Largest, But Declining in Share
Christianity remains the world’s largest religion, with a total of 2.3 billion adherents as of 2020. However, its growth, just 122 million over the decade, has not kept pace with overall population growth. As a result, the Christian share of the global population dropped from 30.6% to 28.8%, a 1.8 percentage point decline.
Pew’s report confirms that Christianity is losing more members through religious switching than any other religion, particularly in the West, where millions are becoming religiously unaffiliated. In contrast, Islam has extremely low attrition rates. While conversion into Islam is statistically small at the global level, Islam continues to gain some followers, particularly in Western prisons and urban areas.
The Future: Islam to Overtake Christianity by 2075
According to earlier Pew projections, if current trends persist, Islam is on track to surpass Christianity as the world’s largest religion by 2075. This seismic shift is being driven by:
- High fertility rates
- Young median age
- High religious retention
- Migration-driven regional expansion
Christianity is projected to grow more slowly and continue losing global share, especially across Europe and North America, where secularization and disaffiliation are rampant.
Civilizational Implications
The implications of this religious and demographic shift are profound. As Islam expands not just in population but in political and cultural influence, Western nations face increasing demands for Sharia-based accommodations, halal regulations, religious exemptions, and Islamic education systems. These pressures are already reshaping national policies in countries like France, Sweden, Germany, and the UK, where Islam is transforming urban demographics and governance.
Islam to dominate the 21st century
Islam is not just the fastest-growing religion; it is poised to reshape the global religious, cultural, and political order. With more than one-third of its followers under age 15, the highest fertility rate of any faith, and expanding influence through migration and religious retention, Islam is positioned to dominate the 21st century.
Meanwhile, Christianity, still numerically dominant, is facing a historic contraction, particularly in the very Western nations where it once stood unchallenged.
