Which European countries saw the fastest increase or decrease in Muslim population from 2000 to 2025?
Executive summary
European Muslim populations have grown steadily since 2000, driven mainly by migration and higher fertility; Pew estimated Europe’s Muslim share rose from 3.8% of the EU in 2010 to 4.9% for Europe in 2016 and projects continued increases under multiple scenarios [1]. Different outlets place Europe’s Muslim total near 44–46 million by the 2010s–2025 and project further growth to mid-century depending on migration—key drivers and national patterns vary by country and dataset [2] [3] [1].
1. Fastest increases: migration hubs and large absolute gains
Countries that have received the most migrants since 2000 show the largest absolute increases in Muslim population. Analysts point to France, Germany, the United Kingdom, Italy and other major destination states as registering the biggest numeric rises because they started with larger Muslim populations and attracted sustained migration flows [3] [2]. Pew’s regional work emphasizes that migration was the single biggest factor driving Muslim growth in Europe between mid-2010 and mid-2016 [1].
2. Fastest increases (percentage terms): smaller countries and Balkan legacies
In percentage terms, smaller Western European countries and parts of the Balkans can show the fastest relative increases because a modest numeric inflow or higher birth rates shifts the share more quickly. Sources highlight that Southeastern Europe contains older, indigenous Muslim communities (Albania, Bosnia, Kosovo, etc.), and growth patterns there differ from Western migration-driven increases [2]. Specific country-by-country percentage rankings for 2000–2025 are not provided in the available sources (not found in current reporting).
3. Why growth happened: migration, youth and fertility
Pew and demographers point to three drivers: international migration into Europe, a younger age structure among Muslims (more children per woman historically), and natural increase. Pew documented that European Muslims are concentrated in younger age groups and historically had a higher fertility rate than non-Muslims, which sustains growth even under a zero-migration scenario [1]. Reporting also notes migration accounted for roughly 50–60% of recent growth in some summaries [3].
4. Where declines occurred: data gaps and assimilation effects
Claims of outright decline in national Muslim populations are not substantiated in these sources for the 2000–2025 window; instead, analysts point to slowing fertility, assimilation, and undercounting as potential downward pressures in some places [2] [4]. Wikipedia-based summaries and commentators warn that conversion out of Islam slightly exceeded conversions into Islam between 2010 and 2016 (roughly 160,000 net loss through conversion in that period), but available sources do not present a list of countries with clear net declines from 2000 to 2025 [2].
5. Projections matter — scenarios change the story
Pew’s scenario approach shows wide variation: under different migration scenarios Europe’s Muslim population trajectory diverges markedly; even with zero migration, the share rises because of age and fertility differentials, while high-migration scenarios produce substantially higher totals by 2050 [1] [5]. Statista reproductions of Pew charts make the same point: scenario choice (zero, medium, high migration) drives projections for country shares through 2050 [5].
6. Disagreement and uncertainty in the sources
Sources disagree on headline totals for 2025 and on how much growth is migration-driven versus natural increase. An Islam-focused compilation places Europe’s 2025 Muslim population at ~46 million (about 6%), while Pew’s baseline for mid-2016 was 25.8 million for EU+Norway+Switzerland and projects higher numbers by 2050 under multiple scenarios [3] [1]. Researchers caution that many European countries do not record religion in census forms, making country-level precision difficult and inviting divergent estimates [2].
7. What the numbers do and do not show (limitations)
Available reporting makes clear drivers (migration, fertility, age structure) but does not supply a definitive ranking of “fastest increase or decrease by country” for 2000–2025 with consistent, comparable national time-series across Europe; those exact country-by-country 2000→2025 growth rates are not present in the current sources (not found in current reporting). Any firm national ranking would require harmonised census or survey time series that many sources note are patchy [2].
8. Bottom line for readers
The pattern is unambiguous in aggregate: Muslim populations in Europe have increased since 2000 and are projected to rise further; the largest numeric increases occurred in migration destinations like France, Germany and the UK, while percentage swings are largest in smaller or historically Muslim-concentrated countries [3] [1] [2]. For a country-by-country, 2000–2025 ranking you will need harmonised national data or a Pew-style dataset broken down to each country year-by-year—available sources here do not provide that full table (not found in current reporting).