A street in Myeong-dong, Seoul
Ratio of 100 working individuals to 30 seniors now could rise to 140 seniors by 2100
South Korea’s population could plummet to just 15 percent of its current level by 2125 if the nation’s ongoing demographic decline continues unabated, according to a private think tank in Seoul on Wednesday.
In its latest long-term forecast, the Korean Peninsula Population Institute for Future used a cohort component method to project Korea’s demographic trends over the next century. This internationally recognized technique estimates future populations by incorporating factors such as birth rates, mortality rates and immigration patterns.
Under the institute’s worst-case scenario, South Korea’s population could drop to 7.53 million by 2125 — a sharp fall from the current 51.68 million. This would be even less than the current population of the city of Seoul alone, which is over 9.3 million.
Even under the most optimistic projection, the population would shrink to 15.73 million, or less than one-third of its current size. The median projection puts the 2125 population at 11.15 million.
The report also highlights the rapidly accelerating pace of population decline. In the median scenario, the population would fall by 30 percent by 2075, and then by more than half over the subsequent 50 years.
This decline is not only due to falling birth rates but also a compounding effect: With fewer people in each successive generation, the pool of potential parents shrinks, further accelerating the decrease.
South Korea’s demographic pyramid, once shaped like a "stingray" with a broad base of younger people, is forecast to morph into a “cobra” shape by 2125, with narrowing bands across all age groups and the population heavily skewed toward older groups.
Population pyramids based on demographic scenarios anticipated in 2050, 2075, 2100 and 2125, from Population Report 2025 (Korean Peninsula Population Institute for Future)
The aging crisis is expected to deepen as well.
In 75 years, the worst forecast is that for every 100 people of working age — defined as 15 to 64 years old — there will be 140 seniors aged 65 or older.
Currently, 100 working-age individuals support around 30 seniors, indicating that South Korea is on track to become an “inverted pyramid” society, where the number of dependents far outnumbers those who provide support.
The report also incorporates a social sentiment analysis based on some 60,000 posts from the workplace community app Blind, focusing on the thoughts of people in their 20s to 40s about marriage and childbirth.
The findings revealed that younger generations now prioritize “money” and “housing” over “love” when discussing marriage. Financial burdens consistently emerged as the dominant concern in the conversations regarding childbirth.
The report concluded that decisions around marriage and parenting are increasingly influenced by economic conditions, rather than personal preference.
The institute proposed a series of urgent policy directions to tackle the crisis, such as expanding support to reduce the burden of childbirth and child-rearing and establishing a practical work-life balance culture. It also emphasized the importance of raising the retirement age and promoting continuous employment while reforming immigration policy.
Above all, the institute stressed the need to restructure the economy around productivity, moving away from a system dependent on demographic growth.
The stark projections underscore the urgent demographic challenge South Korea faces as it grapples with one of the world's lowest birth rates and fastest-aging populations.
As of 2024, South Korea’s total fertility rate — the average number of children a woman is expected to have over her lifetime — has ticked up slightly to 0.75, but it remains well below the replacement level of 2.1.
Which way, Korean man?
