How do 2025 Muslim population estimates compare to 2010 and 2020 census-era figures?

1. Fast growth, clear decade jump: 2010 → 2020

Pew’s 2010–2020 accounting is the clearest benchmark: the number of Muslims rose by 347 million between 2010 and 2020, reaching about 2.0 billion in 2020; Muslims’ share of the global population rose from roughly 24% to 25.6% in that interval ^{[1] [5]}.

2. 2025 estimates cluster but vary by source

Contemporary 2025 estimates are not unanimous. Several data sites and analysts place the 2025 Muslim population between about 2.0 and 2.1 billion, producing world-share figures from ≈24% up to ≈26.4% depending on methodology and population baselines ^{[2] [3] [4] [6]}. Some outlets report a 2025 total near 2.056 billion or “about 2.1 billion,” reflecting differing inputs ^{[6] [3] [4]}.

3. Why numbers differ: methods, baselines, and timing

Differences arise because providers mix census counts, Pew’s reconciled estimates, UN population revisions and projections, and independent aggregations. Pew’s authoritative 2010–2020 series is explicit about methods and covers 201 countries; other 2025 claims often rely on projecting past trends or on national census updates with varying years and quality, producing the 2.0–2.1 billion spread seen in the sources ^{[5] [7] [8]}.

4. Regional dynamics explain most of the change

Pew and related reporting attribute the Muslim population rise chiefly to high fertility and a youthful age structure in Muslim-majority regions (Middle East-North Africa, sub‑Saharan Africa, parts of Asia) and to migration patterns; Asia-Pacific remained home to the most Muslims even as its share shifted slightly ^{[1] [9] [5]}. Sources emphasize that natural increase — births minus deaths — is the dominant driver rather than conversion ^{[1] [10]}.

5. Magnitude: small percent-point gains matter at scale

A roughly 1.8–2 percentage-point gain in world share (from ~24% in 2010 to ~25.6% in 2020) represents hundreds of millions of people because the global population is billions; even modest percentage swings translate to very large absolute changes, as documented by Pew’s 347 million increase 2010–2020 ^{[5] [1]}.

6. Projections and headlines: what to trust and why

Pew’s decade-to-decade assessment remains the most transparent, peer-reviewed-style benchmark for 2010 and 2020; many 2025 figures are projections or compilations that echo Pew’s trajectory but introduce variance through updated UN totals, national census revisions, or proprietary models ^{[5] [8]}. Journalists and analysts should treat 2025 totals in the 2.0–2.1 billion range as plausible consensus estimates while noting methodological spread ^{[3] [4]}.

7. Competing narratives and possible agendas

Some outlets emphasize Islam’s “fastest-growing” status to highlight cultural or political implications; advocacy-leaning sites may amplify larger 2025 totals ^{[10] [2]}. Commercial ranking sites and faith-oriented pages sometimes present rounded or promotional figures (e.g., “over 2 billion”) without full methodological notes, which can create inflated impressions if readers conflate projection with firm census counts ^{[7] [6]}.

8. What’s not settled / data limitations

Available sources do not mention a single global 2025 census or an internationally harmonized 2025 religious enumeration; instead, estimates combine past censuses, demographic surveys and projections. Where national censuses are old or inconsistent, country-level totals feed uncertainty upward into global aggregates ^{[7] [5]}.

9. Bottom line for readers

Between 2010 and 2020 the Muslim population grew dramatically (+347 million to ~2.0 billion in 2020). By 2025 most analysts place the total near 2.0–2.1 billion (roughly 24–26% of the world), but exact 2025 figures vary by data source and method; Pew’s 2010–2020 benchmark remains the strongest public reference point for comparing census-era changes ^{[1] [3] [4]}.