The global population reached a demographic milestone between 2020 and 2025 when the number of people aged 65 and older exceeded the number of children aged 5 and under for the first time in recorded history.

The U.S. Census Bureau detailed the shift in its report "An Aging World: 2025," released August 31. In 2025, the older population stood at 852 million, or 10.5 percent of the world's total of 8.13 billion people. Falling fertility rates and rising life expectancies drove the change, which occurred earlier than many demographers had projected a decade ago.

More than 71 percent of the world's population now lives in countries with fertility rates at or below the replacement level of about 2.1 births per woman, up from 45 percent in 2013. Both China and India, the two largest nations, have fertility below replacement, along with countries such as Bangladesh, Mexico, and Vietnam.

The older population is projected to reach nearly 2 billion by 2060, accounting for roughly 55 percent of all net global population growth during that period. The world total is expected to climb to 10.23 billion, with the share of those 65 and older rising to 19.6 percent.

This inversion places new pressures on labor markets, pension systems, and healthcare infrastructure in many nations. Asia is set to see the largest absolute increase in seniors, while Africa, though remaining the youngest region, will experience a more than fourfold rise in its older population.

The report notes that the trend reflects broad improvements in health and longevity alongside sustained low birth rates across developed and developing economies alike.