Where does half of South Korea's population live?

Half of South Korea's population lives on just 1.4% of its land.

Measured from the GHSL population grid (European Commission JRC, 2025) inside Natural Earth borders. How we measured this

  • The north-west side: half the population, on 11.5% of the land
  • The rest: the other half, on 88.5%

Taller columns mean more people. The dashed line is the most lopsided straight cut that still splits the population exactly in half. Data: GHSL population grid (European Commission JRC, 2025) inside Natural Earth borders.

The straight-line test

Draw one straight line across South Korea so that exactly half the population is on each side. Of all the lines that do it, the most lopsided puts half of everyone on the north-west side, on just 11.5% of the land.

Now cut the land in half instead, at the same angle. That looks like the fair cut, but the north-west half ends up with 71.6% of the people. Both figures are our measurements from the GHSL population grid (European Commission JRC, 2025) inside Natural Earth borders.

That gap between how a country looks and where its people are is exactly what Slice is about.

Why half of South Korea lives around Seoul

The Seoul Capital Area (Seoul, Incheon and Gyeonggi Province) covers only about 12% of the country, but it is home to about 51% of South Korea's population, according to government figures for the end of 2025 reported by the Korea Herald. More people live in and around the capital than in the rest of the country put together.

The rest of the land is hard to build on: mountains cover about 70% of the Korean Peninsula, especially in the east and north. So even outside the capital, Koreans live packed into cities: urban areas make up 16.7% of the country's territory but hold 92.1% of its people.

Think you can do better? Try splitting South Korea yourself.

Now you know where everyone lives, so this should be easy, right? In Slice you get one straight line to cut South Korea's population exactly in half, and a second try if you need it. Then the country splits and the population rises in columns, to show how close you got.

Split South Korea yourselfOr play today's puzzle: four new countries

Free, no sign-up. Practice never touches your daily score or streak.

South Korea in Slice after a cut: the country split in two, its population rising in columns, with each side's share labelled.

How we measured this

Every figure on this page comes from the same data as the game: the GHSL population grid (European Commission JRC, 2025) inside Natural Earth borders, which estimates how many people live in each 1 km square. We draw the country on an equal-area map, so every square kilometre counts the same.

“1.4% of its land” counts the most crowded 1 km squares first, until they hold half the people. It measures how tightly people pack, which is why it comes out much smaller than maps that colour whole cities or counties. The straight-line figures test a cut at every angle, one degree apart.

Sources