South Korea's Fertility Rate Is 0.72 — By 2050 It Will Be Older Than Japan

Ask for the world's oldest country and most people say Japan, and the current data backs that up — among the 53 countries this site tracks, Japan's 65-and-over share is the highest in 2025, at 30.0%. That ranking doesn't hold for long. The UN's medium-variant population projections put South Korea's 65-and-over share at 39.7% by 2050, edging past Japan's 37.5%. In 2025, Korea (20.3%) looks nowhere close to Japan's aging level. By 2050, the two swap places.

The root of the reversal is fertility. South Korea's 2023 total fertility rate was 0.72 births per woman — the lowest of the 53 countries in this dataset. This report first sorts those 53 countries into fertility bands to place Korea, then compares the population pyramids of five of them — Korea, Japan, Italy, Jordan, and India — at two points in time, 2025 and 2050, to see how the shape itself changes. One caveat up front: the 2050 figures are UN medium-variant projections, not measurements.

Nine of the 53 countries kept a fertility rate of 2.0 or higher. Uzbekistan leads at 3.50, followed by Egypt (2.75), Jordan (2.64), Cambodia (2.58), Guyana (2.41), Saudi Arabia (2.28), the Dominican Republic (2.24), Morocco (2.23), and Indonesia (2.13). The commonly cited 'replacement rate' needed to hold a population steady is about 2.1 — all nine clear that bar. Flip it around, though, and the other 44 countries (83% of the dataset) have already fallen below the level where domestic births alone can sustain their population.

The other 44 countries all sit below 2.0, and 42 of those are clustered in the 1-point-something range — everything from India (1.98), the Philippines (1.92), and Vietnam (1.91) near the top of that band, to France (1.66), relatively high for Western Europe, down to already-familiar low-fertility countries like Japan (1.20), Italy (1.21), and Thailand (1.21). Only two countries in this dataset have dropped to 1.0 or below: China (1.00) and South Korea (0.72). Even China comes in 39% higher than Korea.

South Korea's fertility rate was 4.53 in 1970. By 2023 it had fallen to 0.72 — a sixth of where it started, in about half a century. It had already dropped below 1.0 by 2020 (0.84) and kept falling from there. That pace is the part a single ranking number doesn't convey: Italy and Japan drifted down over decades, while Korea dropped into territory no other country in this dataset has reached, within two generations.

Some fertility numbers in this ranking shouldn't be read at face value. Gulf states like Qatar (1.73), the UAE (1.20), and Bahrain (1.82) post low fertility rates, but a large share of their population is working-age foreign labor, not the product of low domestic birth rates — their population pyramids bulge in the middle for a completely different reason than Korea's or Japan's do. North Korea's figure (1.78) needs its own caveat: its census data isn't published the way most countries' is, so this number is a UN estimate rather than a directly reported statistic.

Break down South Korea's 2025 population by age band and you get 10.2% under 15, 69.5% working-age (15-64), and 20.3% 65 and older. Once the 65+ share passes 20%, demographers commonly call that a 'super-aged' population — Korea has already crossed that line. The shape looks very different by 2050: the UN's medium-variant projection puts it at 7.8% under 15, 52.5% working-age, and 39.7% 65 and older. Total population falls from 51.67 million to 45.14 million, a 12.6% drop — and within that, the 80-and-older slice alone more than triples, from 4.9% to 16.1%.

Read differently: for every 100 working-age Koreans, the number of people 65 and older to support goes from about 29 in 2025 to about 76 in 2050 — a 2.6x jump in the burden ratio over 25 years. Comparing to Japan shows why the pace matters. Japan already has a higher 65+ share in 2025 (30.0%, well above Korea's), but it only climbs 7.5 points by 2050 (to 37.5%). Korea climbs 19.4 points over the same span (20.3% to 39.7%) — more than double Japan's rate of change. Japan got old first. Korea is getting old faster.

This isn't purely an East Asian pattern. Italy's 65+ share rises from 25.1% in 2025 to 36.8% in 2050, tracking a similar curve to Korea and Japan. Its increase (11.7 points) is about 60% of Korea's (19.4 points), though — all three countries converge on a 36-40% range by 2050, they just arrive at different speeds.

Jordan and India tell a completely different story. In Jordan, under-15s make up 30.2% of the 2025 population — nearly a third — while the 65+ share is just 4.8%. By 2050 it's still young: the 65+ share rises to 12.1%, but the working-age share (65.1%) barely moves. Its total population grows from 11.52 million to 16.37 million, up 42.1%. India follows a similar pattern — 65+ rises from 7.4% to 14.7%, still in single digits for most of that span, while its population grows 14.7%. While Korea's population shrinks, Jordan's and India's keep growing.

Every 2050 figure here is a UN medium-variant projection, built on the assumption that current fertility, migration, and life-expectancy trends roughly continue for 25 more years — policy shifts or social change could move the actual outcome. Korea's decline has been unusually steep even by regional standards, which means its projection likely carries a wider margin of error than most.

A separate report comparing Korea and Japan on income, happiness, and livability covers more of that relationship from other angles. Each country's current median age and life expectancy are available on its detail page. Fertility rates here come from World Bank data; age-band population figures come from the UN Population Division's World Population Prospects.