Place comparison
South Korea compared with Japan: area, population and density
Japan has about 3.8 times South Korea’s area but only about 2.4 times its population, so South Korea is about 1.6 times as dense.
Equal-area outline comparison
Outlines are centered and scaled by official land area; position does not show geographic location.
Area
Population
Population density
Area data date
Population data date
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The guide below belongs to this pair: South Korea and Japan. Change the selector above and the page follows, so the reading always matches the tool.
Direct answer
How different are South Korea and Japan?
South Korea covers 100,459.9 km² (38,788 sq mi); South Korea's area is about 26.6% of Japan's. Its reported population is 51,805,547; South Korea's population is about 41.8% of Japan's. By average density, South Korea's population density is 1.57 times Japan's.
Population difference
South Korea's population is about 41.8% of Japan's 51,805,547 · 123,802,000Density difference
South Korea's population density is 1.57 times Japan's 515.7 /km² (1,336 /sq mi) · 327.5 /km² (848 /sq mi)Full data and sources for each place: South Korea area & population, Japan area & population
Straight-line distance between geometric centres: about 925 km; time difference: none.
On a familiar scale
- South Korea ≈ the size of Virginia (reference rung) 1,939 m² of land per resident
- Japan ≈ 94% of California 3,053 m² of land per resident
Reference scales come from U.S. Census Bureau: 2025 Gazetteer Files: land area of states and counties , as of 2025-01-01.
How to read it
Japan has far more land, but South Korea packs more people onto each square kilometre.
Geography and shape
South Korea holds the southern part of the Korean Peninsula, bounded by sea on three sides, with lowlands in the west and south and mountains along the east coast. Japan is an archipelago whose four main islands alone — Honshu, Hokkaido, Kyushu and Shikoku — cover well over three times South Korea’s area.
Population context
Japan’s 123,802,000 people (October 2024 estimate) are about 2.4 times South Korea’s 51,805,547 (2024 register-based census). South Korea averages about 516 people per km², Japan about 328.
Boundaries and definitions
South Korea’s area is registered cadastral land and its population a register-based census that counts Korean and foreign residents. Japan’s area is the Geospatial Information Authority’s national territory figure, including the Northern Territories, and its population the Statistics Bureau’s estimate. Both are official national figures, but they are not measured the same way.
South Korea: Register-based census population, including Korean and foreign residents; registered cadastral land area.
Japan: Total population estimate and national territory area.
In-depth guide
How should South Korea and Japan be understood in context?
Japan has nearly four times South Korea’s land but well under three times its people. That is why South Korea — not Japan — is the more crowded of the two on average, about 516 people per km² against Japan’s 328.
Measured with Japan’s own islands
South Korea’s 100,460 km² is about 1.28 times Hokkaido (78,419 km² without the Northern Territories), about 2.7 times Kyushu (36,781 km²) and about 44% of Honshu (227,943 km²).
A rough picture for Japanese readers: Hokkaido plus Kyushu (115,200 km²) is about 15% more than all of South Korea.
Why South Korea is the denser one
Japan’s population is about 2.4 times South Korea’s, but its land is about 3.8 times larger, so each square kilometre in South Korea carries about 1.6 times as many people on average. Both countries are mountainous, so the lived-in lowlands are far denser than either national average.
The Seoul area makes the point sharper: Seoul alone holds about 9.3 million people on 605 km², close to the population of Tokyo’s 23 wards on almost the same area.
Questions people ask
About this geographic comparison
Which is bigger, South Korea or Japan?
Japan is bigger, with a land area about 3.76× that of South Korea (South Korea 100,459.9 vs Japan 377,975.6 km², or 38,788 sq mi vs 145,937 sq mi).
How big is South Korea compared to Japan?
Japan has 377,975.6 km² (145,937 sq mi) and South Korea has 100,459.9 km² (38,788 sq mi): the ratio is 3.76×. Conversely, South Korea has 26.6% of Japan's area.
Does South Korea or Japan have more people?
Japan has 123,802,000 people (2024-10-01), versus 51,805,547 in South Korea (2024-11-01): 2.39×. In reverse, South Korea has 41.8% of Japan's population. South Korea is 26.6% the size of Japan — 100,459.9 km² vs 377,975.6 km² (38,788 sq mi vs 145,937 sq mi). Population is 41.8% as high; average density is 1.57× higher. Each side’s scope and reference date are set out under “Boundaries and definitions” on this page.
Is South Korea bigger than Japan?
No. Japan is bigger, with a land area about 3.76× that of South Korea (South Korea 100,459.9 vs Japan 377,975.6 km², or 38,788 sq mi vs 145,937 sq mi). The area difference is 277,515.7 km². Japan has 377,975.6 km² (145,937 sq mi) and South Korea has 100,459.9 km² (38,788 sq mi): the ratio is 3.76×. Conversely, South Korea has 26.6% of Japan's area.
How many times bigger than South Korea is Japan?
About 3.8 times by area: 377,976 km² against 100,460 km². By population only about 2.4 times.
Which part of Japan is about the size of South Korea?
South Korea is about 1.3 times Hokkaido (78,419 km², excluding the Northern Territories) and about 44% of Honshu. The whole Korean Peninsula, North and South together, is about the size of Honshu.
Sources
- Statistics Korea: 2024 Population and Housing Census (Register-based Census)
- e-Nara Index, Republic of Korea: National land area by administrative region (year-end 2024)
- Statistics Bureau of Japan: Current Population Estimates as of October 1, 2024
- Geospatial Information Authority of Japan: Area by prefecture and municipality
Outline data:
- Natural Earth · Public domain