Presented by Zia H Shah MD

Using demographic data and projections from reputable sources (Pew Research Center and United Nations data), we can estimate the cumulative number of births worldwide from 2000 through 2025 for major religious groups. The table below summarizes the approximate totals of live births to mothers of each faith over this 25-year period:

Demographic Assumptions and Drivers: These estimates are derived from global demographic models that incorporate fertility rates, population age structures, and regional population distributions:

• Fertility Rates: Muslim families have had the highest fertility rates (roughly 2.9 children per woman in recent years), followed by Christian families (around 2.6). No other major faith group has a fertility rate above the global average (about 2.4), with Hindu fertility around 2.3 and Buddhist fertility well below replacement level​christianitytoday.com​ pewresearch.org. Higher fertility means a larger share of global births. For example, between 2010 and 2015, about 223 million babies were born to Christian mothers vs. 213 million to Muslim mothers​pewresearch.org, even though Muslims were only ~24% of the world population at that time. This is because Muslim populations tend to be younger and have more children on average.
• Age Structure: The age distribution of each religious group influences birth totals. Muslim populations are, on average, younger, with a higher proportion in childbearing years, leading to a birth share (~30% of global births in 2010–2015) that exceeds their population share ​pewresearch.org. Christian populations, while large, include older age cohorts (especially in Europe) that contribute to higher death rates, but Christians still accounted for about one-third of global births in 2000–2025 due to growing youthful populations in Africa and other regions​pewresearch.org.
• Regional Concentration: The majority of Hindus live in South Asia (primarily India, which is home to ~94% of the global Hindu population ​pewresearch.org). India’s fertility decline over the period has significantly reduced the number of Hindu births. Pew projections show a drop-off in Hindu birth numbers – by mid-century, the annual births among Hindus are projected to be tens of millions lower than in the 2010s ​pewresearch.org. This trend is reflected in the ~0.5 billion cumulative Hindu births (2000–2025), which accounts for a smaller share of world births than Hindus’ share of the population, due to steadily falling fertility in India and surrounding countries.
• Low-Fertility Populations: Buddhists represent a much smaller fraction of global births. Many Buddhist-majority populations (e.g. in China, Thailand, Japan) are aging and have low fertility rates, leading to slow growth or even decline in their overall numbers ​pewresearch.org. Consequently, Buddhist mothers contributed only on the order of a few hundred million births over the 25-year span. In 2010–2015, births to Buddhists (and other smaller groups like Jews and folk religions) were modest – Pew notes that births exceeded deaths even for these groups in that period, but their contribution to the global birth total was relatively small ​pewresearch.org.
• Population Growth vs. Conversion: These birth estimates assume that changes in religious population are driven mainly by natural increase (births minus deaths). Conversions and religious switching have only a minor net impact globally compared to birth rates. Pew’s models (which use United Nations demographic projections as a foundation) indicate that differences in fertility and mortality overshadow conversion patterns​ christianitytoday.com ​okilab.es. For example, even though Christianity is projected to experience some net losses from religious switching (especially to the “unaffiliated” category) on the order of a few million, these are small relative to the hundreds of millions of births in Christian families ​christianitytoday.com​. Similarly, Islam’s growth is almost entirely due to higher birth rates rather than conversion ​christianitytoday.com. The estimates above thus primarily reflect demographic assumptions (fertility, mortality, age structure, and migration) from reputable sources ​okilab.es, rather than large-scale religious conversions.

Sources: Pew Research Center demographic reports ​pewresearch.org ​pewresearch.org ​pewresearch.org (which provide data on births by religion for 2010–2015 and projections through 2050) were used alongside United Nations population data to extrapolate totals back to 2000. Additional context on fertility rates and regional demographics comes from Pew’s Global Religious Futures studies and academic analyses ​christianitytoday.com​ pewresearch.org. These sources consistently highlight that the 2000–2025 period saw on the order of one billion births each among Christians and Muslims, about half a billion among Hindus, and a much smaller total among Buddhists – reflecting the differing fertility patterns and age distributions of these populations worldwide. All figures above are rounded estimates, but they illustrate the clear dominance of Christian and Muslim births (roughly 70% of global births combined) in recent decades, with Hindu and Buddhist birth totals trailing in accordance with their population size and fertility trends​pewresearch.org ​christianitytoday.com.