Youngest Populations in the World: Countries Where Half Are Under 20

The world's youngest countries are concentrated in Sub-Saharan Africa, where high fertility rates and improving child survival have created massive youth bulges. Niger leads with a median age of just 14.9 years — meaning half the country is younger than a high school student.

Introduction

These young populations represent enormous potential: a demographic dividend that could drive economic growth if education and employment expand. But without sufficient investment, youth bulges can lead to unemployment, instability, and mass migration.

1. Niger

• Median Age: 14.9 years
• Fertility Rate: 6.7 children per woman
• Under-15 Population: 50.6%
• Population Growth: 3.7% per year

Niger has the youngest population and highest fertility rate of any country on Earth. The average Nigerien woman has nearly 7 children, and population is projected to quadruple from 27 million to over 100 million by 2060.

Only 36% of Niger's population can read and write, and just 2% of women use modern contraception. The country faces a stark challenge: its population is growing far faster than its economy, schools, or healthcare system can accommodate.

2. Uganda

• Median Age: 15.7 years
• Fertility Rate: 4.7 children per woman
• Under-15 Population: 46.5%
• Population Growth: 3.0% per year

Uganda is one of the fastest-growing countries in Africa with one of the youngest populations globally. By 2050, Uganda could have more people than Germany — despite being one-third the size.

Kampala's average resident is in their early 20s, creating a vibrant but strained urban culture. Youth unemployment exceeds 30%, and the government has prioritized vocational training and ICT education to harness the demographic dividend.

3. Mali

• Median Age: 15.8 years
• Fertility Rate: 5.9 children per woman
• Under-15 Population: 47.3%
• Population Growth: 3.0% per year

Mali's extremely young population is driven by cultural preferences for large families, limited access to education (especially for girls), and low contraception use (17% of women).

The Sahel region faces a compounding crisis: rapid population growth is outpacing food production in an area increasingly affected by desertification and climate change. Bamako, the capital, has grown from 650,000 in 1990 to over 4 million today.

4. Chad

• Median Age: 16.1 years
• Fertility Rate: 6.1 children per woman
• Under-15 Population: 47.0%
• Population Growth: 3.1% per year

Chad has one of the world's youngest and fastest-growing populations despite being one of the poorest countries. Just 22% of adults can read, and only one-third of children complete primary school.

N'Djamena, the capital, is growing at 5% per year as rural Chadians flee drought and conflict. The city lacks basic infrastructure — less than 10% of residents have access to a sewer system, and electricity reaches fewer than 15% of the national population.

5. Angola

• Median Age: 16.7 years
• Fertility Rate: 5.3 children per woman
• Under-15 Population: 46.0%
• Population Growth: 3.2% per year

Angola's young population is partly a legacy of its brutal 27-year civil war (1975-2002), which decimated a generation and drove birth rates higher in the aftermath. Oil wealth has funded development, but inequality remains extreme.

Luanda is one of the most expensive cities in the world for expatriates, yet 70% of its residents live in informal settlements. Angola invests just 2.4% of GDP in education, far below the Sub-Saharan African average of 4.1%.

Key Facts

• 25 countries have median ages below 18 — all in Sub-Saharan Africa
• Africa's population under 25 will reach 1 billion by 2050
• Niger's population has grown from 3.5 million (1960) to 27 million (2025)
• The global median age is 30.5 years — double Niger's
• Youth (15-24) unemployment exceeds 30% in many of the youngest countries

Fun Facts

• Niger adds a city the size of Phoenix (1.6 million) to its population every year
• In Uganda, only 2% of the population is over 65
• If Africa's youth were their own country, it would be the world's third most populous
• The youngest country in Europe (Kosovo, median age 30) is still twice as old as Niger

Final Thoughts

The world's youngest populations represent both humanity's greatest potential and its most urgent challenge. Countries with massive youth bulges can reap a demographic dividend of economic growth — but only if education, healthcare, and job creation keep pace with population growth. The choices these nations make in the next two decades will shape the world for the rest of the century.