What are official estimates vs. academic estimates for Muslim populations in Europe in 2025?
Executive summary
Official tallies and many secondary estimates put Europe's Muslim population in 2025 at roughly 45–46 million people, about 6% of the continent’s roughly 744–745 million inhabitants (an “official” aggregation reflected in recent compendia) [1] [2]. Academic estimates converge on a similar mid‑40 million figure but repeatedly warn that methodological gaps — uneven census practices, legal bans on collecting religious data in some countries, and differing definitions of “Muslim” — make any single number provisional and contested [3] [4].
1. How the “official” number — ~46 million — is being reported
Multiple recent summaries and data aggregations treat 46 million Muslims in Europe in 2025 as the working figure, representing about 6% of Europe’s population; outlets drawing on national censuses, demographic offices and organizations such as Pew present values in this band [1] [2]. Those compilations typically combine national counts where religion is recorded with modeled estimates for countries that do not collect religion in censuses, producing continent‑wide totals summarized in journalistic pieces that explicitly cite Pew and national statistical agencies as primary inputs [1] [2].
2. What academics and research centers actually say
Academic work and major demographic centers such as Pew present estimates in the same general neighborhood but emphasize uncertainty: Pew’s earlier series put Muslims at about 6% of Europe in 2020 (around 45.6 million) and projects trajectories using fertility, migration and age‑structure models — approaches academics favor — producing numbers close to the mid‑40 millions for the mid‑2020s [3]. Researchers also decompose growth drivers, attributing a large share to migration and a smaller but important share to differential fertility, nuances that aggregated “official” media totals sometimes elide [2] [3].
3. Why numbers vary: legal, methodological and definitional problems
A central source of divergence is uneven data collection: several European countries legally prohibit asking about religion in official censuses (France under laïcité is a prominent example), while others collect varying proxies such as country of birth, nationality or self‑reported religious practice, forcing academics to model estimates rather than rely solely on headcounts [4] [3]. Even where surveys exist, categories differ — counting “people of Muslim background,” active adherents, or those born in Muslim‑majority countries produces different totals, and some city‑level claims (for example on Muslim shares of schoolchildren) have been flagged as inflated or misleading when methodological limits are ignored [4].
4. Migration and fertility: academic breakdown of population dynamics
Scholars emphasize that recent growth is driven more by migration than by conversion, and that fertility differences explain part but not all of the trend: one synthesis cited attributes roughly half of recent growth to migration and the remainder to higher fertility among Muslim populations, with Muslim total fertility rates estimated above the European average in several studies [2] [3]. Academics additionally note fertility convergence over time — second and third generations tend to have lower fertility — which complicates simple extrapolations from current age‑structure snapshots [3].
5. Where reporting may mislead: inflated city figures and selective citations
Fact‑checking has shown that viral charts and some media claims overstate local Muslim shares by mixing non‑comparable datasets or by applying national proxies to city populations; Reuters has flagged examples where projected schoolchild percentages and city claims exceeded what primary sources support, underscoring the risk of cherry‑picking or over‑generalization in popular summaries [4]. This does not invalidate continent‑wide mid‑40 million estimates but cautions readers that localized percentages — and panicky narratives about “replacement” or imminent demographic dominance — rest on shaky methodological ground and selective use of sources [4] [3].
6. Bottom line and where uncertainty remains
Both official compilations and academic analyses converge on a 2025 estimate of roughly 45–46 million Muslims in Europe (~6%), but the confidence interval around that figure is wide because of inconsistent national practices, definitional choices, and rapid recent migration flows that require model adjustments [1] [2] [3]. Where reporting departs from that consensus — asserting very large city‑level shares or dramatic near‑term shifts — it often reflects methodological shortcuts or agenda‑driven framing rather than new empirical breakthroughs, a point underscored by targeted fact‑checks [4].