In 2018, for the first time in recorded human history, the global population aged 65 and older, roughly 705 million people, exceeded the global population aged zero to four, roughly 680 million. That crossover happened squarely within Generation Alpha’s birth years, and it captures something the cohort’s “largest generation in history” branding tends to obscure: Generation Alpha is growing up in the first period of human history where the world’s oldest residents outnumber its youngest.
Who Is Generation Alpha
Generation Alpha, coined by Australian social researcher Mark McCrindle in a 2008 report, is generally defined as people born between 2010 and 2024, following Generation Z and preceding Generation Beta. Some organizations use slightly different endpoints, including a 2013-to-2025 range used by the Annie E. Casey Foundation, but McCrindle’s 2010-2024 definition is the most widely cited. Generation Alpha is the first generation to be born entirely within the 21st century and, by most counts, is expected to be the largest generation in history at close to 2 billion people once its births are complete.
Generation Alpha is primarily the children of Millennials, alongside older members of Generation Z. It is also, by U.S. Census Bureau data, the most racially and ethnically diverse generation on record in the United States, with Hispanic and multiracial shares notably higher than in the general population.
The Demographic World Generation Alpha Was Born Into
Generation Alpha’s birth years overlap almost exactly with a documented global fertility slide. The global fertility rate fell from about 2.5 births per woman near 2010 to roughly 2.2 by 2024, continuing a longer decline from about 4.7 in 1950 and 2.4 in 2017. About half of the world’s countries had already reached sub-replacement fertility by the mid-2010s, a threshold that continued expanding through Generation Alpha’s childhood to cover more than half of all countries and areas by 2024.
The 2018 crossover between the world’s over-65 and under-5 populations is the starkest single marker of this shift. The UN projects the ratio between these two age groups will exceed 2 to 1 by 2050, meaning the world’s elderly population will be more than double its youngest age group well before the youngest members of Generation Alpha reach middle age. Generation Alpha is, in that specific sense, the last generation to grow up as the world’s population structure tips decisively toward age rather than youth.
Global Age Structure Milestones
| Year | Population Aged 0-4 | Population Aged 65+ | Note |
|---|---|---|---|
| 2018 | approx. 680 million | approx. 705 million | First recorded crossover, elderly exceed youngest children |
| 2024 | approx. 630-650 million (est.) | approx. 800 million+ | Gap widening |
| 2050 (projected) | Declining | Ratio to under-5s projected to exceed 2:1 | UN projection |
Generation Alpha and the Global Child Population
McCrindle’s public estimates put Generation Alpha’s eventual size at close to 2 billion, or roughly 2.1 billion by some counts, once all births through 2024 are counted, a figure built from roughly 2.8 million Generation Alpha births occurring globally each week during the cohort’s peak years. That would make it larger than Millennials (roughly 2.0 billion births over 1981-1996) and roughly comparable to Generation Z (roughly 2.1 billion births over 1997-2012), continuing a pattern where each successive 15-year generation has landed in a similar range because global annual births have stayed relatively steady even as fertility per woman has fallen, an effect of population momentum from earlier, larger generations of parents.
Where Generation Alpha Is Growing Up
Generation Alpha’s geographic distribution mirrors the same regional fertility divide that will carry through to Generation Beta. Sub-Saharan Africa and South Asia together account for roughly half of the world’s children, while East Asia and Europe, despite large populations, contribute a shrinking share of the world’s youngest age groups each year.
| Region | Approx. Share of World’s Under-15 Population | Approx. Regional Fertility Rate |
|---|---|---|
| Sub-Saharan Africa | approx. 28-29% | approx. 4.3 |
| South Asia | approx. 24-25% | approx. 2.2 |
| East Asia and Pacific | approx. 15-16% | approx. 1.4 |
| Latin America and Caribbean | approx. 8% | approx. 1.8 |
| Middle East and North Africa | approx. 8% | approx. 2.7 |
| Europe and Central Asia | approx. 6-7% | approx. 1.5 |
| North America | approx. 3% | approx. 1.6 |
A child in Niger, where fertility remains near 6 to 7 births per woman, grows up in a household and national environment radically different from a child in Italy or South Korea, where fertility sits near or below 1.2. Both fall within the Generation Alpha birth-year range. Almost nothing else about their demographic circumstances is shared.
Smaller Families and Changing Childhood
Generation Alpha, more than any previous generation outside the very lowest-fertility countries, is likely to grow up with fewer siblings than its parents did. Millennials, born mostly to Baby Boomers and older Generation X parents during a period of higher fertility, tended to come from larger households on average than Generation Alpha children born to Millennial parents in the 2010s and 2020s, a period when fertility had already fallen substantially in most of the countries producing large numbers of Millennial parents.
This shift is compounded by rising parental age. Mean age at first birth has climbed across most OECD countries and increasingly across East Asia, meaning a larger share of Generation Alpha children have parents in their thirties rather than their twenties compared with earlier generations, itself a factor that tends to correlate with smaller eventual family size.
Generation Alpha and Population Aging
A useful, counterintuitive way to understand Generation Alpha’s demographic position is that it can be the largest generation in absolute history while still growing up in societies experiencing historic aging. These are not contradictory facts. Generation Alpha’s raw size, close to 2 billion, is a function of population momentum, a very large number of Millennial and Gen Z parents having children even at reduced fertility rates. Population aging, meanwhile, reflects the growing number and share of people surviving into their sixties, seventies, and eighties, a separate trend driven by rising life expectancy rather than by how many children are being born.
Global life expectancy rose from about 52 years in 1960 to roughly 72 years by 2017, and has continued climbing modestly since. That improvement, combined with falling fertility, is what produced the 2018 crossover between the world’s elderly and youngest child populations, and it means Generation Alpha children in most countries will grow up alongside a larger relative share of grandparents and great-grandparents than any earlier generation experienced.
The World Gen Alpha Will Enter as Adults
By the time the oldest members of Generation Alpha reach their thirties in the mid-2040s, they will be entering labor markets and family-formation decisions in a world with a meaningfully older overall population than exists today. Old-age dependency ratios, the number of people 65 and older relative to the working-age population, are projected to keep rising across most high-income and middle-income countries through the 2040s and 2050s, driven by both continued longevity gains and the aging of large Millennial and Generation X cohorts.
At the same time, in high-fertility countries across Sub-Saharan Africa, Generation Alpha adults will enter labor markets with a comparatively young population structure and, potentially, a demographic dividend opportunity if education and employment systems can absorb a large working-age cohort. The world Generation Alpha inherits as adults will therefore look as divided by geography as the world they were born into as children, just shifted forward by roughly two to three decades.
Key Findings
- The global population aged 65 and older first exceeded the population aged zero to four in 2018, a milestone that occurred within Generation Alpha’s birth years and is projected to widen to a greater than 2-to-1 ratio by 2050.
- Generation Alpha is expected to reach close to 2 billion people, roughly comparable in size to Millennials and Generation Z, since global annual births have remained relatively stable across all three generational windows despite falling fertility per woman.
- Sub-Saharan Africa and South Asia together account for roughly half of the world’s under-15 population, while East Asia and Europe contribute a shrinking share each year.
- Global fertility fell from about 2.5 births per woman near Generation Alpha’s 2010 start to about 2.2 by 2024, continuing a longer decline from 4.7 in 1950.
- Generation Alpha in the United States is the most racially and ethnically diverse generation on record, according to Census Bureau data, though this pattern is specific to countries with significant recent immigration and is not a universal Generation Alpha characteristic worldwide.
Conclusion
Generation Alpha’s “largest generation in history” framing captures only the most visible half of its demographic story. The less-discussed half is that this cohort is growing up in the first period of recorded history where the world’s elderly outnumber its youngest children, a crossover that happened in 2018 and is set to widen sharply by 2050. Generation Alpha is simultaneously the product of demographic momentum built up by earlier, larger generations and the first cohort to fully inherit the aging world that momentum is now giving way to.
Frequently Asked Questions
1. How many people are in Generation Alpha?
Generation Alpha is commonly estimated at close to 2 billion people globally, based on McCrindle Research projections built from roughly 2.8 million births occurring worldwide each week during its peak years, though this figure is a private-sector estimate rather than an official UN cohort count.
2. Where is Generation Alpha largest?
Sub-Saharan Africa and South Asia together account for roughly half of the world’s under-15 population, making them home to the largest absolute share of Generation Alpha, even though cultural discussion of the cohort is often centered on wealthier, lower-fertility countries.
3. Will Generation Alpha have fewer siblings than earlier generations?
In most countries, yes. Global fertility has fallen substantially since the Baby Boomer and early Generation X eras, and rising parental age at first birth in many countries further correlates with smaller eventual family sizes.
4. What demographic changes will Generation Alpha experience as adults?
The oldest members of Generation Alpha will enter adulthood in the 2030s and 2040s facing rising old-age dependency ratios in most high-income and middle-income countries, alongside continued high youth populations and potential demographic dividend opportunities in parts of Sub-Saharan Africa.
5. Is Generation Alpha really the largest generation in history?
It is commonly described that way, at close to 2 billion people, though Millennials and Generation Z are estimated in a similar range, meaning the “largest” distinction is narrow and depends on exactly which birth-year boundaries and estimation methods are used.
6. Why did the world’s elderly population overtake its youngest children in 2018?
The crossover reflects two simultaneous trends: rising life expectancy, which increased the number of people surviving into their sixties and beyond, and falling fertility, which reduced the number of children born each year, together producing a structural shift toward an older global population.
7. Is Generation Alpha’s diversity a global pattern or a specific-country pattern?
It is largely specific to countries with significant recent immigration, such as the United States, where Generation Alpha is the most racially and ethnically diverse generation on record. This is not a universal global demographic feature of the cohort.
8. How does population aging affect Generation Alpha’s childhood?
A larger relative share of the world’s population is now over 65 than at any point in recorded history, meaning Generation Alpha children in most countries are growing up alongside proportionally more grandparents and great-grandparents than earlier generations did.
9. Does a large generation mean fast population growth?
Not necessarily. Generation Alpha’s large absolute size mostly reflects population momentum from earlier, larger parent generations rather than rising fertility, since fertility per woman has actually been falling throughout Generation Alpha’s birth years.
10. How does Generation Alpha compare to Generation Beta demographically?
Generation Beta is being born into a world with even lower global fertility, more countries at peak population, and a wider gap between growing and shrinking nations than existed during Generation Alpha’s early childhood, making Beta’s demographic environment a continuation and intensification of trends visible during Alpha’s own birth years.
Sources
- Wikipedia, “Demographics of Generation Alpha,” citing UN and World Bank data
- Britannica, “Generation Alpha” topic entry
- United Nations, Department of Economic and Social Affairs, Population Division, World Population Prospects 2024
- United Nations, World Fertility 2024 report
- McCrindle Research, “The Generation Alpha Report” and related public commentary
- U.S. Census Bureau, generational population and diversity data
- Axios, “A landmark generation: Introducing Gen Alpha,” January 2024
