World Population Data (2018)

  • The population of 26 countries, nearly all in Africa, will at least double. Niger in West Africa will see its population nearly triple.
  • A total of 38 countries will have smaller populations in 2050 than in 2018. China will register the largest numerical population decrease―about 50 million―followed by Japan at 25 million and Russia at 9.4 million. Romania will see the largest percentage decline in population (23 percent).
  • The population of the United States will reach 390 million, up from 328 million in 2018.
  • China’s population will decrease by about 50 million from its current size to 1.34 billion. India will supplant China as the world’s most populous country with 1.68 billion people.
  • Nigeria will become the third most populous country as its population rises to 411 million, up 109 percent from 2018. Nigeria is currently the seventh most populous country.


  • The world population will reach 9.9 billion in 2050, up 29 percent or 2.3 billion from an estimated 7.6 billion now.
  • Africa’s population will more than double by 2050 to 2.6 billion and the continent will account for 58 percent of the global population increase between 2018 and 2050.
  • By 2050, the number of people in Asia will rise about 717 million to 5.3 billion, while Europe (including Russia) will see a decline in population from 746 million to 730 million. The population in the Americas is seen increasing to 1.2 billion from 1 billion now.
  • The population of 26 countries, nearly all in Africa, will at least double by 2050. The population of Niger in West Africa will nearly triple.
  • The population of 38 countries will be smaller in 2050 than in 2018. The biggest numerical decrease will be in China (about 50 million) and the biggest percentage decrease in Romania (around 22 percent).


  • The 2018 worldwide total fertility rate (TFR) is 2.4. The global TFR has been declining but remains high enough to drive continued global population growth. Niger has the highest TFR at 7.2; South Korea the lowest at 1.1.
  • As the global population increases, continued declines in fertility and mortality mean that the world population’s shift toward an older age structure (known as population aging) will accelerate.
  • PRB projects that 16 percent of the world population will be ages 65+ by 2050, up from 9 percent in 2018, and 5 percent in 1960. The segment ages 85+ is growing the fastest among this age group.
  • The share of children (ages <15) in the world population has been falling and will continue to fall, from 37 percent in 1960, to 26 percent in 2018, and a projected 21 percent by 2050.
  • Age structures, as well as the timing and speed of age structure change, vary by country and have implications for national policy agendas and resource allocation.