Japan vs South Korea

Japan is 3.8 times larger than South Korea — 377,915 against 99,720 km². Japan is 2.4 times more populous than South Korea — 123,366,734 against 51,684,564 people.

Side by side

Population density

South Korea is 1.6 times more densely populated than Japan — 518 against 326 people per km². Density is where area and population interact, and it often reverses the impression the headline figures give — a large country with a small population can feel emptier than a small crowded one by an enormous margin.

Practical differences

• They drive on opposite sides — Japan on the left, South Korea on the right.
• Different currencies: the Japanese yen and the South Korean won.

Japan

A 2023 government survey using digital mapping counted 14,125 islands, more than double the long-quoted figure of 6,852. About three-quarters of the land is mountain, so nearly everyone lives on a narrow band of coastal plain. Japan sits where four tectonic plates meet and records a fifth of the world's magnitude-6-and-above earthquakes.

South Korea

About seventy percent mountain, so the population is packed into the valleys and coastal plains; the Seoul metropolitan area holds roughly half the country. Jeju Island is a shield volcano whose lava tube system is among the finest in the world. South Korea has the fastest average internet connections of any large country.

Neutral facts only. Nothing here addresses politics, government, economics or which country is preferable in any respect — population is the one figure that dates, and it carries its year.