The largest age group globally is the under 20 years old demographic, representing over a third of the world's population, followed closely by the 20-39 age bracket, with Africa having the youngest populations and Europe the oldest; however, the 65+ group is the fastest-growing segment, expected to outnumber children by 2080, as the world's median age rises.
The global age distribution reveals that nearly half of the world's population (47.5%) falls between the ages of 20 and 54.
The median age of the world is about 30.6, which means about half the current world population was born before 1994 and half after. If you can remember the 80s at all you're probably a minority.
Globally, about 25 percent of the population is under 15 years of age and 10 percent is over 65 years of age.
Today, the largest age group in America is people in their 30s, numbering close to 47 million. In 2019, Millennials surpassed Baby Boomers as the biggest generation, and their share of the population is expected to peak by 2033. Moreover, immigration is projected to be a major driver of this growth.
As a demographic cohort, Generation Z is smaller than the baby boomers and their children, the Millennials. According to the U.S. Census Bureau, Generation Z makes up about one quarter of the U.S. population, as of 2015.
In 2021, the largest age group in Australia was 30 to 34 year olds. The group that changed the most since 2016 was 35 to 39 year olds, increasing by 277,133 people. The Age Structure of Australia provides key insights into the level of demand for age based services and facilities such as child care.
Japan's population is aging faster than any other country on the planet. The population of those 65 years or older roughly doubled in 24 years, from 7.1% of the population in 1970 to 14.1% in 1994. The same increase took 61 years in Italy, 85 years in Sweden, and 115 years in France.
A supercentenarian, sometimes hyphenated as super-centenarian, is a person who has reached the age of 110 years. This age milestone is only achieved by about one in a thousand centenarians. Even rarer is a person who has lived to 115.
Generation Alpha has now surpassed all other generations, making up 24.4% of the global population
Monaco is the country with the highest median age in the world. The population has a median age of around 57 years, which is around six years more than in Japan and Saint Pierre and Miquelon – the other countries that make up the top three.
"Global majority" is a collective term for people of African, Asian, indigenous, Latin American, or mixed-heritage backgrounds, who constitute approximately 85 percent of the global population.
The 20-40 age group is broadly called Young Adults, encompassing the "20-somethings" (vicenarians) and "30-somethings" (tricenarians), often aligning with the Millennial generation, though specific labels vary by context (e.g., social science, marketing, or demographic research).
Top 10 Countries With World's Oldest Population
It is common in demography to split the population into three broad age groups:
The participants were monitored until they died or turned 90. At the end of the study, about 16% of the men and about 34% of the women survived to the age of 90. In fact, the authors found women who were taller than 5 feet 9 inches were 31% more likely to reach 90, compared to those who were under 5 feet 3 inches.
In it, he talks about how the ages of 22–42 are statistically the most unhappy period in life. Why? People come out of their early 20s and think life is supposed to be easy, but it's not. Those two decades are full of challenges.
In the United States in 2021, the death rate was highest among those aged 85 and over, with about 17,190.5 men and 14,914.5 women per 100,000 of the population passing away. For all ages, the death rate was at 1,118.2 per 100,000 of the population for males, and 970.8 per 100,000 of the population for women.
Adulthood prime (maximal performance age) begins when growth in height terminates or the velocity slows to an almost imperceptible rate. For women this occurs, on average, by 18-20 years and for men the typical ages are 20-23 years. The Prime adult years continue until about age 30-35 years in both sexes.
Australia has an ageing demographic. The proportion of the Australian population aged 65 and over was 15% in 2017, a trend which is expected to continue to grow. It is estimated that by 2057 older people will account for 22% of the Australian population which translates to 8.8 million people.
- Ethnicities with higher melanin content: African, South Asian, and Mediterranean ethnicities tend to show fewer signs of sun-induced aging, such as wrinkles and age spots, due to their increased melanin levels.
Findings indicated that non-Hispanic Blacks and Hispanics have accelerated aging, and non-Hispanic Whites have decelerated aging. Racial/ethnic differences were strongly tied to educational attainment. We also observed a significant difference by birthplace for Hispanics.
Key statistics
In 2021, 26% of households in Australia contained only one person, compared with 24.4% in Greater Capital Cities, with the most dominant household size being 2 persons per household.
JUNE 26, 2025 — The U.S. population age 65 and older rose by 3.1% (to 61.2 million) while the population under age 18 decreased by 0.2% (to 73.1 million) from 2023 to 2024, according to the Vintage 2024 Population Estimates released today by the U.S. Census Bureau.