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The story of humanity is written in numbers. In 1800, the world’s population hovered around just 1 billion. By 1950, it had doubled. Today, humanity has surged past 8 billion — and projections suggest we could reach10.3 billion in the 2080s.
This staggering expansion did not occur uniformly from country to country. Some countries leaped early to the fore, while others are only now emerging on the world stage. And looking ahead, the balance will continue to shift dramatically.
For instance, whereas the population in Europe is stabilizing or diminishing, nations such as Nigeria and Ethiopia will experience explosive growth in the coming decades.
One thing that has remained constant over the course of history, though, is the imposing shadow of India and China. The two giants have consistently dominated the list of the world’s most populated countries, shaping global demographics century after century.
Curious about how specific nations have reached the milestone population levels throughout the decades — and how they’ll keep on changing?
To find out, I created a series of maps based on Wikipedia’s List of Population Milestones by Country database.
20 Million Population Milestone
Crossing the 20 million mark was like lighting a great bonfire — a signal that a civilization had grown too large to ignore. Only a few ancient societies reached it early: China likely passed 20 million by 1000 B.C., Persia by 480 B.C., Greece by 400 B.C., and Rome by 60 B.C. France joined around 1100 A.D., the Mali Empire by 1400, and ancient Mexico around 1250 A.D. In the modern era, Russia crossed the line in 1765, Germany by 1770, and Japan by 1815, though likely earlier. Britain reached 20 million during the early Victorian surge in 1837, and the U.S. soon followed in 1844. After World War II, a wave of nations joined — Egypt, Thailand, South Korea, and the Philippines by the 1950s, with Nigeria notably reaching it earlier in 1933. Today, new countries like Kazakhstan (2023) and Zambia (2024) continue this climb, while places like Guatemala and even the Netherlands (projected 2059) are still on the journey.
50 Million Population Milestone
Aside from the ancient giants — India (most likely around 727 B.C.) and China (around 147 B.C.) — no modern country crossed the 50 million mark until much later.
The first major modern powers to break the 50 million mark were Russia in 1872 and the United States in 1879, driven by farm technologies, expansion to the west, and industrialization. Germany later followed in 1893, capitalizing on the upsurge of unification and economic change.
Japan went over the hump in 1911, following its dizzying modernization during the Meiji period. Indonesia came next in 1925, followed by the United Kingdom and Brazil in 1948, both of which owed their existence to the early 20th-century population reorganizations.
Reaching 50 million was like setting anchor as a serious demographic force — a symbol of internal growth and global influence.
Today, many countries have passed this number, but for much of history, it was an exclusive club marking a nation’s rise onto the world stage.
100 Million Milestone
The leap to 100 million was historically rare and transformative.
India likely surpassed this mark by 664 A.D., and China by 1175 A.D., centuries before anyone else.
In the modern world, the United States hit 100 million first, in 1914, riding a tidal wave of immigration and industrial progress. Russia reached 100 million in 1948, just after the immense upheavals of World War II.
Then came a demographic surge across the world:
Indonesia (1965)
Japan (1967)
Brazil (1972)
Pakistan and Bangladesh (both 1988)
Nigeria (1992)
Mexico (1999)
Philippines (2014)
Ethiopia (2016)
Egypt (2019)
Democratic Republic of the Congo (2021)
Vietnam (2023)
And many more, such as Tanzania, Iran, and Uganda, are projected to follow in the coming decades.
Crossing 100 million often signals not just growth but a tipping point in a nation’s economy, politics, and global influence.
200 Million Milestone
Few nations have yet crossed the huge 200 million threshold. China and India, of course, did so long ago in their histories. More recently, the United States reached 200 million in 1967, during the height of the Baby Boom years.
Indonesia reached it in 1997, driven by urbanization and steady growth.
Pakistan joined this exclusive club in 2018, driven by one of the world’s highest population growth rates. Brazil crossed 200 million in 2012, a reflection of its rise as a continental power.
Several countries should reach 200 million in the not-too-distant future:
Bangladesh (~2038)
Ethiopia (~2043)
Democratic Republic of the Congo (~2046)
Tanzania (~2069)
Egypt (~2091)
500 Million Milestone
Only two nations have reached half a billion:
China, by 1933 (though historians think it may have happened slightly earlier).
India, around 1966, after a century of steady agricultural and urban growth.
No other nation — yet — has even come close.
1 Billion Milestone
The 1 billion milestone redefines the possible.
China crossed 1 billion people in 1981, at the beginning of its economic awakening.
India followed in 1997, and continues to expand, recently becoming the world’s most populous country (2023).
No other country has yet crossed this mind-bending threshold, though Nigeria is expected to by late this century.
Here’s the complete journey of population milestones, spanning an incredible range — from 20 million all the way to 2 billion!
What do you believe the future holds for world population growth? Will any new nations surprise us by reaching these milestones? Let us know in the comments below!
