Geopolitics › East Asia › South Korea (Republic of Korea)
South Korea's record-low fertility
Below 1.0 since 2018; 0.72 in 2023, 0.80 in 2025· Issue or flashpoint
FactTreaties, membership, measured data, events.
South Korea has the world's lowest fertility rate, about 0.8 children per woman, far below the 2.1 needed to keep population stable.
See it on the Geopolitics map →The picture
The rate fell below 1.0 in 2018 and hit 0.72 in 2023, then rose to 0.75 in 2024 and 0.80 in 2025 as marriages rebounded after COVID; births reached about 254,500. Seoul's rate was 0.63. Causes include costly housing, long work hours, heavy cram-school spending and the career penalty women face. Governments have spent over $200 billion on incentives since 2006 with little effect. The population peaked in 2020, and over 20% of Koreans are now 65 or older.
Why it matters
A shrinking workforce threatens growth, pensions and the military; South Korea is the extreme test case for aging societies, including China and Japan.
Think of it like
Like a building where leases keep expiring and too few new tenants sign: occupancy holds for a while, then drops fast.
Key facts and numbers
Official birth statistics released in February 2026, Statistics Korea population projections and government spending reports.
What to watch
Whether the 2024–25 uptick is a lasting turn or a brief post-COVID marriage bounce; official projections still show the population falling to about 36 million by 2072.
Connections (2)
▸South Korea's record-low fertility is the extreme case in Demographics: aging and population shiftsFact
The relationship
At about 0.8 children per woman, South Korea is furthest along a path many rich countries, and China, are following. At that rate each generation is about 40% the size of the one before. Its experience, from closing schools to shrinking army intake, previews what rapid aging means for economies and security.
Since when and why
Nationwide, sharpest in Seoul; below 1.0 since 2018, with a low of 0.72 in 2023 and about 0.80 in 2025.
How we know
Statistics Korea birth data and UN comparisons ranking it the world's lowest; the arithmetic of generational shrinkage is straightforward.
What to watch
Whether the small 2024–25 rebound lasts, and whether others, such as Taiwan and China, sink to similar levels, are open questions.
▸South Korea's record-low fertility is shrinking the military of South Korea (Republic of Korea)Fact
The relationship
Fewer births mean fewer conscripts. South Korea's active forces fell from about 563,000 in 2019 to about 450,000 by mid-2025, and the number of 20-year-old men dropped 30% to about 230,000. Units have been merged or disbanded, while North Korea keeps an army more than twice as large.
Since when and why
Defense Ministry figures reported in August 2025; men serve about 18 months in the army.
How we know
Defense Ministry data, defense white papers and Statistics Korea population projections.
What to watch
Whether drones, automation and more career soldiers can offset the shrinking pool, and whether conscripting women enters serious debate.