World Population in 2100: The World After the Peak

By the populationclock.org team · Published October 19, 2026 · All figures: UN World Population Prospects 2024, medium variant

The short answer

On the medium variant of the UN World Population Prospects 2024, the world holds roughly 10.19 billion people at the start of 2100, against about 8.27 billion today. That is a gain of something like 1.92 billion across 74 years, which sounds substantial until you set it beside the 5.79 billion added between 1950 and now. The century ahead adds a fraction of what the century behind us did, and it does not add it steadily. We track the full path on our world population in 2100 page.

The more important fact about 2100 is that it is not the high point. The projection peaks in 2084 at about 10.29 billion and then turns down, so the 2100 figure is roughly 103 million below the maximum, about as many people as live in Vietnam today. By the start of 2100 the world is shrinking at about 0.13% a year, where today it grows at around 0.83%. The timing of the turn is the subject of our separate article on when world population peaks.

The last decades of the century undo the ones before

A projection that ends at 10.19 billion hides the shape of how it gets there. The world first reaches that level around 2071, climbs for roughly 13 more years, and then spends the rest of the century coming back down to where it already was. Anyone reading only the endpoints would conclude that the second half of this century was uneventful. In the projection it holds the one event with no precedent anywhere in this dataset: the moment the number stops going up.

What produces the turn is not a catastrophe but arithmetic. Worldwide births already peaked, in 2012, at about 146 million a year. Today there are around 363,023 births a day against roughly 174,349 deaths, a subject we take apart in how many people are born every day. By 2100 births have fallen to about 301,448 a day while deaths have risen to roughly 336,774. Deaths overtake births worldwide around 2084, and after that the population falls on its own, with no change in anybody’s behaviour required.

Deaths rise because the population is large and old, not because anything has gone wrong. A world holding many more old people buries many more each year, even while life expectancy keeps improving. That is the part of the projection most often misread as pessimism.

Where the people are

The regional balance in 2100 looks very little like today’s. Asia still holds the largest single share, but it falls from about 59% of the world to roughly 45%. Africa rises from about 19% to 37%, adding 2.24 billion people along the way, which is more than the world gains in total. Europe falls from around 9% to 6% and is 151 million smaller than today. Only Africa, Northern America and Oceania are still growing when the projection horizon arrives. The fuller account of the African side of this is in the African century.

The size rankings get rewritten

Ten countries hold the top of the table today, and 2 of the ten are different by 2100. Today 2 of the ten largest countries are African; in 2100 4 of them are. DR Congo climbs from 15th to 5th. The United States keeps growing throughout and still slips from 3rd to 6th, passed by Pakistan, Nigeria and DR Congo on the way down.

Both columns are computed from the same dataset and the same scenario. Brazil and Russia leave the top ten entirely. The sortable version is our largest countries in 2100 ranking.

One country is most of the subtraction

Of the 237 countries and territories in the dataset, 122 are larger in 2100 than today and 115 are smaller. The losses are concentrated to a degree that is easy to miss. China alone falls from about 1.41 billion to 639 million, a loss of roughly 776 million people, which is about 64% of every person subtracted from every shrinking country combined. The rest of the decline is spread thin across Europe, East Asia and the Caribbean. Our shrinking countries ranking lists them in order.

India is the other number worth pausing on. It remains the largest country in the world in 2100 at about 1.51 billion, and it is still 192 million below its own peak, reached around 2062. Being first at the end of the century and being past your maximum are not mutually exclusive: 161 of the 237 entries in the dataset have already peaked before 2100 arrives, and they hold about 48% of the world’s people in that year.

An old world almost everywhere

The aging is the most uniform thing in the projection. Today 5 places in the dataset have a median age of 50 or more, and among them only Japan has more than a million people. By 2100 the count is 70. At the other end, 38 places currently have a median age under 20, the lowest of them around 15. In 2100 not one does: the youngest median age anywhere in the dataset is Côte d'Ivoire, at roughly 31.

Fertility converges the same way: 56 countries and territories currently average three or more births per woman; by 2100 the projection has none doing so, and 224 of 237 sit below the replacement level of about 2.1. The world of 2100 in this dataset is not a world divided into fast growers and shrinkers. It is a world where nearly everyone has the same low birth rate and the differences come from how long ago they got there, a convergence we trace in the fertility line most of the world is now below.

How much of this should you believe

Less than the precision suggests, and that caveat is bigger here than for any nearer date. The UN publishes low and high fertility variants alongside the central one. For 2050 they span about 1.42 billion. For 2100 they span 7.33 billion: from roughly 7.02 billion to about 14.35 billion. The low end is smaller than the world today, and under that variant population peaks as early as 2053 at around 8.95 billion. The high end is still climbing when the projection stops.

That spread is not a defect of the modelling. It is the honest consequence of projecting three generations who are not yet born, where small differences in assumed family size compound into billions. Most of the people alive in 2050 have already been born, which is why the nearer figure in our world population in 2050 piece is comparatively solid. Almost nobody alive in 2100 has been born yet.

What survives the uncertainty is the shape rather than the level. Births per year are already falling, the young populations that would reverse that do not exist, and even the high variant ends the century growing at about 0.58% a year, slower than the world grows today. Figures here are the UN World Population Prospects 2024 medium variant, aggregated as described in our methodology. A projection is a conditional statement about what follows from a set of assumptions, not a forecast, and a number carrying a decimal point for the year 2100 should be read as direction and scale.