Countries with the Youngest Populations (Median Age, 2024)

Data

Note: Why Some Populations Are So Young

What the data shows

Median age is the age that splits a population into two equal halves: half of all residents are younger than that figure and half are older. Unlike an average age, it is not dragged around by a small number of very elderly people, which makes it the cleanest single measure of whether a society is young or old.

• Niger is the youngest country on Earth: its median age of 15.2 means half the population has not yet had a 16th birthday.
• Uganda (16.2), Angola (16.3), Mali (16.4), and Chad (16.7) complete the top five.
• Every single country in the top 20 is African, and 17 of the 20 are in sub-Saharan Africa.
• Sierra Leone closes the list at 19.4, still younger than nearly every country outside Africa.
• The global median age in 2024 is about 31.0, so these countries are roughly 15 years younger than the world average.

How a median age is calculated

Demographers sort every person in a country by age, youngest to oldest, and then take the person sitting exactly in the middle. That midpoint is the median. A country with a median age of 16 is not simply "full of children"; it is a population where children genuinely outnumber adults, usually because families are large and birth rates are high.

• It is a snapshot, not a projection: the figures here come from the UN World Population Prospects 2024 estimates for each country's resident population.
• Median age says nothing about how fast a population grows, only where the middle sits.
• Two countries can have the same median age but very different shapes: one with a baby boom, another with heavy immigration.
• Demographers pair median age with fertility rate, life expectancy, and dependency ratios to tell the full story.

Why sub-Saharan Africa is so young

The main driver is fertility. Sub-Saharan Africa still has the highest birth rates in the world, with many countries reporting four to seven children per woman. High birth rates continuously add young cohorts at the bottom of the age pyramid, which keeps the midpoint pinned at a low age even as life expectancy climbs.

• Niger's fertility rate is around 6.7 children per woman, among the highest anywhere on Earth.
• Chad, Mali, and the DR Congo average five or more children per woman, and most of the other countries on the list average more than four.
• Falling child mortality also matters: as more infants survive, the young share of the population grows even when birth rates hold steady.
• Life expectancy in these countries is lower than in rich nations, which trims the older end of the pyramid and pushes the median down further.
• Africa as a whole is the youngest continent, with a median age near 19, while Europe is the oldest at around 44.

What a young population means

A youthful age structure is a double-edged sword. When fertility starts falling, countries enjoy a "demographic dividend": a large working-age share with fewer dependents, which historically powered rapid growth in East Asia. But while birth rates remain very high, the same structure means many children per worker, heavy pressure on schools, and a big wave of job seekers arriving every year.

• In Niger, more than 40% of the population is under 15, so spending on education and health must absorb a huge cohort.
• Nigeria and the DR Congo, the two most populous countries on this list, add millions of new working-age people each year.
• If jobs lag behind, the youth bulge raises risks of unemployment and migration pressure; if investment lands, it fuels one of the fastest-growing workforces in history.
• United Nations projections show these countries will keep growing quickly this century, with Niger's population expected to more than triple by 2100.

How the list is changing

Even the youngest countries are slowly ageing. Comparing the 2020 and 2024 medians, most entries moved up by 0.2 to 1.0 years as fertility edges downward across the continent. Senegal is a rare exception, dipping slightly from 19.4 to 19.2.

• Guinea-Bissau, Burundi, and Zambia are tied at 18.4, a reminder that a single decimal can separate several countries.
• Twenty years from now the same list will likely look broadly similar, but several countries will have crossed into the low 20s as the demographic transition advances.
• The contrast with the oldest countries is stark: Monaco sits at 56.9, almost four times Niger's figure, and Japan at 49.9.

Fun facts

• Niger's median age of 15.2 is the lowest of any sovereign state in the world.
• Half the top 20 sits at 18.4 or younger, meaning a typical citizen in those countries is still a teenager.
• Africa's overall median age of about 19 is roughly half of Europe's, the largest continental gap on Earth.
• The world's median age was about 24 in 1950 and is about 31 today, so even the global population is ageing steadily.
• Countries like South Korea and Japan, which are at the top of the oldest list, will flip to shrinking workforces in coming decades while these young nations keep expanding.
• Demographers call a population "young" when more than 30% of people are under 15, a threshold nearly every country on this list clears.