Compare · UN World Population Prospects 2024

Japan and Nigeria, side by side

Japan in 2026: half the people are older than 51. Nigeria: half are older than 19.

UN estimates for mid-2023: Japan 124,370,946 people · Nigeria 227,882,945

Japan 122 million people Half are older than 51 30 in 100 are 65 or older

Nigeria 242 million people Half are older than 19 3 in 100 are 65 or older

How to read this: each pyramid stacks a place’s people by age — babies at the bottom, the oldest at the top, men on the left and women on the right. A wide bottom means many children; a wide top means many older people.

Compare shapes Compare sizes

Each bar is a share of its own place’s people, so a small country and a large one can be read side by side.

Year 2026 · UN projection

estimatesprojections

men women projected

Verified 2026-09-30 · 73 canaries

JPN × NGA · 2026 · age groups

If each place were 100 people

Shrink each population to 100 people and count them. Dots are children under 15, filled squares are people aged 15 to 64, and open squares are people 65 and over. The picture follows the year slider above.

Japan

Children, under 15: 11
Aged 15 to 64: 59
Aged 65 and over: 30

Nigeria

Children, under 15: 40
Aged 15 to 64: 57
Aged 65 and over: 3

JPN × NGA · families and lifetimes

Children, and how long lives last

Japan is at about 1.2 children for each woman, at this year's rates; Nigeria is at about 4.2. Around 2.1 children per woman keeps a population the same size over time, leaving migration aside. Life expectancy at birth this year: about 85 years in Japan, about 55 in Nigeria.

Children per woman, 2026

Each figure is one child: how many children a woman would have in her lifetime at that year’s rates.

Japan 1.2

Nigeria 4.2

The dashed line at 2.1 is about what it takes for each generation to replace the one before it, leaving migration aside.

How long a newborn can expect to live, 2026

Each block is ten years of life, if the death rates of that year stayed the same all life long.

Japan 85 years

Nigeria 55 years

Hatched marks are UN projections (medium variant), not measurements.

JPN × NGA · 1950–2100 · how many

How big, and where they are heading

There are 242 million people in Nigeria and 122 million in Japan: about twice as many people as Japan.

Japan's population is 1.4 times what it was in 1950; Nigeria's population is 6.5 times what it was in 1950.

Japan's population peaked in 2009. Meanwhile Nigeria's population is still growing in 2100. In 2100: 76.8 million in Japan, 477 million in Nigeria (UN projection, medium).

Show the numbers

Year	Japan: people	Nigeria: people	Japan: half older than	Nigeria: half older than	Japan: children per woman	Nigeria: children per woman	Japan: life expectancy	Nigeria: life expectancy
1950	86.4433 million	37.2830 million	22.3	19.1	3.62	6.42	59.3	35.5
1960	96.3997 million	45.0538 million	25.7	19.3	1.98	6.36	67.7	37.2
1970	106.712 million	55.8938 million	29.3	18.9	2.04	6.47	72.0	40.0
1980	118.359 million	73.7646 million	32.7	17.7	1.74	6.85	76.1	46.0
1990	123.400 million	97.1209 million	37.9	17.2	1.51	6.46	79.0	45.7
2000	127.028 million	126.382 million	41.8	17.8	1.35	6.12	81.2	47.1
2010	128.185 million	166.643 million	45.2	17.7	1.36	5.95	82.9	51.3
2023	124.371 million	227.883 million	50.0	18.8	1.21	4.48	84.7	54.5
2030*	119.584 million	262.381 million	52.5	20.3	1.26	3.82	85.7	55.5
2040*	112.158 million	312.710 million	54.1	22.7	1.31	3.10	87.1	57.1
2050*	105.123 million	359.186 million	53.8	24.9	1.35	2.66	88.4	58.5
2060*	98.1032 million	399.785 million	54.1	27.3	1.39	2.39	89.7	59.9
2070*	90.6118 million	433.486 million	54.6	29.8	1.42	2.20	90.9	61.2
2080*	84.7300 million	457.922 million	53.7	32.0	1.44	2.07	92.1	62.5
2090*	80.6344 million	471.886 million	53.4	33.8	1.46	1.98	93.2	63.6
2100*	76.8460 million	476.748 million	54.0	35.3	1.47	1.91	94.4	64.7

* UN projection, medium variant. People at mid-year; ages and life expectancy in years.

JPN − NGA · 1950–2100 · every age

Which ages each place has more of

Each column is a year and each row an age, from babies at the bottom to 100 at the top. The shade of a cell shows which place has more of its people at that age — the key beside the picture tells you which shade is Japan and which is Nigeria, and the in-between shade means the same. Because it compares shares, a small place and a large one can be compared fairly.

236 countries · 1950–2100

Where they sit among all countries

Every country in the world, every year from 1950 to 2100. The grey cloud shows where most countries are; Japan is drawn in solid blue squares and Nigeria in open orange squares, so you can see whether each is ahead of the crowd, behind it or in the middle.

More comparisons

Keep exploring

Each place on its own: Japan · Nigeria. Or pick any two places with the boxes at the top of this page.

Other comparisons

Apparatus

Sources and method

Japan and Nigeria are drawn here from one source and one release: the UN Population Division's World Population Prospects 2024, counted through 2023 and projected on its medium variant after that. Two places read off the same tables can be set against each other; two read off different tables cannot.

The working behind the median age, the rounding in the “100 people” pictures and the reason the regions are kept out of the all-country views are all set out in the method.

250 comparisons have a page of their own; any other two places can be compared from the boxes at the top.

Sources: UN WPP 2024 · flag-icons. Every source, its licence and how to cite it →

Verified 2026-09-30 · 73 canaries