simplemaplab

Japan vs UK Size: How Much Bigger Is Japan?

By Marko Visic · Updated Nov 11, 2026

Japan covers 145,914 sq mi (377,915 km²) and the United Kingdom 94,058 sq mi (243,610 km²), so by total area Japan is 1.55× the UK, larger by 51,855 sq mi. Japan has 1.79× as many people, the larger economy in US dollars and 2.39× as much coastline, yet on a Mercator world map the UK looks the bigger of the two.

The United Kingdom drawn to scale over Japan. By total area Japan is 1.55 times the UK.Japan is 1.55× the size of the UK by total areaJapan 145,914 sq mi · UK 94,058 sq mi · total areaJapanUKsimplemaplab.com/size-comparisons/japan-vs-uk · CC-BY 4.0
The United Kingdom drawn over Japan, both in equal-area projections at one scale. The UK's area is 64% of Japan's.
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Japan vs UK by the numbers

MetricJapanUKRatio
Total area (sq mi)145,91494,058Japan 1.55×
Land area (sq mi)140,72893,410Japan 1.51×
Population (Japan 2024 est.; UK 2025 est.)123,201,94568,751,311Japan 1.79×
People per sq mi of land875736Japan 1.19×
GDP, current US$ (2025)$4.45T$4.01TJapan 1.11×
GDP at PPP (2025)$7.03T$4.57TJapan 1.54×
GDP per person, current US$$36,145$58,359UK 1.61×
Coastline (mi)18,4867,723Japan 2.39×
Highest pointMount Fuji, 12,388 ftBen Nevis, 4,413 ftJapan 2.81×
Mean elevation1,437 ft531 ftJapan 2.70×
Standard timeUTC+9UTC+0
First-level divisions47 prefecturesEngland, Scotland, Wales, Northern Ireland

Ratios divide the larger figure by the smaller. GDP per person divides the IMF figure by the Factbook population of each country.

Which is bigger: Japan or the UK?

Japan. Its total area of 145,914 sq mi is 1.55× the UK's 94,058 sq mi, a difference of 51,855 sq mi, about the size of Louisiana (52,378 sq mi). On land alone the ratio is 1.51: 140,728 against 93,410 sq mi. The CIA World Factbook describes Japan as “slightly smaller than California” and the UK as “slightly smaller than Oregon.”

Islands and coastlines

The Factbook describes Japan as composed of four main islands, Hokkaido, Honshu, Shikoku and Kyushu, and its area includes outlying groups such as the Ryukyu and Bonin Islands. In February 2023 the Geospatial Information Authority of Japan counted 14,125 islands, every naturally formed piece of land with a perimeter of at least 328 ft (0.1 km) on its maps plus the islands defined in law. That count replaced the figure of 6,852 that the Japan Coast Guard published in 1987. The UK's area in the Factbook includes the Shetland Islands and Rockall.

The Factbook gives Japan 18,486 mi (29,751 km) of coastline and the UK 7,723 mi (12,429 km), so Japan's is 2.39× as long. It also notes that no place in the UK is more than 78 mi (125 km) from tidal waters.

Population and the economy

Japan had 123,201,945 people in the CIA World Factbook's 2024 estimate and the UK 68,751,311 in its 2025 estimate, so Japan has 1.79× as many (123.2 million against 68.8 million). Per square mile of land that is 875 people in Japan and 736 in the UK.

In the IMF World Economic Outlook (October 2026), Japan's GDP in 2025 was $4.45 trillion and the UK's $4.01 trillion in current US dollars, so Japan's economy was 1.11× the UK's. At purchasing power parity Japan's lead is 1.54×, $7.03 trillion against $4.57 trillion. Per person the UK is ahead: about $58,359 against $36,145 in Japan.

Why the UK can look bigger than Japan on a world map

A Mercator map enlarges area by 1/cos² of the latitude: about 1.6× at 37.5° and 2.4× at 50°. The UK is farther from the equator than Japan. Computed from our map data with a Mercator projection, the UK's outline is enlarged 2.93× and Japan's 1.60×, so on such a map the UK looks 1.18 times the size of Japan, though Japan is 1.55 times the UK.

Drawn to scale: Japan next to the UK

Both countries at the same area per pixel, side by side.

Japan and the United Kingdom side by side at the same equal-area scale.Japan is 1.55× the UK by total areaJapan145,914 sq miUnited Kingdom94,058 sq mi
Japan in a conic equal-area projection (parallels 33°N and 41°N), the UK in one with parallels 50°N and 58°N, at one scale.

Methodology and sources

Area
CIA World Factbook, final edition: Japan and CIA World Factbook, final edition: United Kingdom (total and land area). US states in comparisons: US Census Bureau, State Area Measurements and Internal Point Coordinates (2010).
Population
CIA World Factbook: Japan 2024 estimate, UK 2025 estimate.
GDP
IMF World Economic Outlook (October 2026), GDP in current US dollars (2025) and IMF World Economic Outlook (October 2026), GDP at purchasing power parity (2025), both countries from the same release. GDP per person divides that GDP by the populations above.
Islands
Geospatial Information Authority of Japan, press release “我が国の島を数えました” (We counted Japan's islands), February 28, 2023. Main islands and outlying groups: CIA World Factbook.
Coastline, elevation, time, divisions
CIA World Factbook, final edition: Japan and CIA World Factbook, final edition: United Kingdom. Miles and feet are converted from the Factbook's kilometers and meters.
Drawings
Shapes from us-atlas (US Census Bureau cartographic boundaries) and world-atlas (Natural Earth 1:50m) for the drawings, scaled to total area. Mercator factors are computed from the same map data with a Mercator projection.

Frequently asked questions

Yes. Japan covers 145,914 sq mi (377,915 km²) and the UK 94,058 sq mi (243,610 km²), so by total area Japan is 1.55× the UK, larger by 51,855 sq mi, about the size of Louisiana.
Japan has 140,728 sq mi of land and the UK 93,410 sq mi, a ratio of 1.51. The rest of each total is water: 5,185 sq mi in Japan and 649 sq mi in the UK (CIA World Factbook).
Japan. It had 123,201,945 people in the CIA World Factbook's 2024 estimate and the UK 68,751,311 in its 2025 estimate, so Japan has 1.79× as many. Per square mile of land that is 875 people in Japan and 736 in the UK.
Japan. In the IMF World Economic Outlook (October 2026), its GDP in 2025 was $4.45 trillion against the UK's $4.01 trillion in current US dollars, 1.11×, and $7.03 trillion against $4.57 trillion at purchasing power parity, 1.54×. Per person the UK is ahead, about $58,359 against $36,145.
14,125, in a count the Geospatial Information Authority of Japan announced on February 28, 2023. It counted naturally formed land with a perimeter of at least 328 ft (0.1 km) on its maps, plus islands defined in law. The count replaced the figure of 6,852 that the Japan Coast Guard published in 1987; the authority attributes the difference mainly to more detailed maps.
Japan: 18,486 mi (29,751 km) against the UK's 7,723 mi (12,429 km), 2.39× as long on the CIA World Factbook's figures. The Factbook adds that no place in the UK is more than 78 mi (125 km) from tidal waters.
Japan. Mount Fuji rises to 12,388 ft (3,776 m) and Ben Nevis, the UK's highest point, to 4,413 ft (1,345 m), so Fuji is 2.81× as high. The mean elevation is 1,437 ft (438 m) in Japan and 531 ft (162 m) in the UK (CIA World Factbook).
Japan's standard time is UTC+9 and the UK's is UTC+0, nine hours apart (CIA World Factbook).
A Mercator map enlarges area more the farther a place is from the equator, and the UK is farther north. Computed from our map data with a Mercator projection, the UK's outline is enlarged 2.93× and Japan's 1.60×, so on such a map the UK looks 1.18 times the size of Japan, though Japan is 1.55 times the UK.
The CIA World Factbook describes Japan as "slightly smaller than California" and the UK as "twice the size of Pennsylvania; slightly smaller than Oregon." By land area California has 1.11× Japan's land and Oregon 1.03× the UK's (Census 2010 for the states).
Japan has 47 prefectures. The UK is made up of England, Scotland, Wales and Northern Ireland, which cover 53%, 32%, 9% and 6% of its area (CIA World Factbook).

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Suggested citation: SimpleMapLab (2026). Japan vs UK Size. Retrieved from https://www.simplemaplab.com/size-comparisons/japan-vs-uk. CC-BY 4.0.