How Many Islands Does Japan Have? The Recount That Tripled the Map

Ask a textbook how many islands Japan has and, until recently, it answered 6,852. That figure came from a 1987 survey by the Japan Coast Guard, compiled from paper charts. In February 2023 the Geospatial Information Authority of Japan (GSI) published the first recount in 35 years — this time from digital national maps — and the answer more than doubled: 14,125 islands.

What counted, and what changed

The GSI counted land masses of at least 100 metres in circumference shown on its digital maps, applying the same definition as the old survey. No new land had appeared: the difference was the map. Thousands of small islands that paper charts had merged, missed or drawn too coarsely to count were suddenly visible. The definition matters more than the number — depending on the source and the minimum size used, you will also see figures of roughly 400 inhabited islands (the transport ministry counts 418) and, of those, 255 inhabited islands designated for development support under the Remote Islands Development Act, grouped into 77 areas.

Where the islands are

By prefecture, the island map is dominated by the south-west: Nagasaki, Kagoshima and Okinawa hold long chains of inhabited islands — the Gotō Islands, the Tokara and Amami chains, the Kerama, Miyako and Yaeyama groups — while Hokkaidō's inhabited islands can be counted on two hands. Tokyo, surprisingly, administers two of the most remote groups of all: the Izu Islands and the Ogasawara (Bonin) Islands, the latter a full day by sea from the capital that governs them.

How this guide chose its islands

This guide covers the inhabited islands that travellers actually go to, together with the largest inhabited islands by population — the islands with ferries to catch, villages to stay in and articles worth reading. Every island here has its own page with its population, area, municipality and the full text of its encyclopedia article. The four main islands (Honshū, Hokkaidō, Kyūshū and Shikoku) and Okinawa's main island are where the journeys start, so they are not listed as destinations in themselves; the list begins where the ferry leaves.

Sources: Geospatial Information Authority of Japan, island recount (February 2023); Ministry of Land, Infrastructure, Transport and Tourism remote-island materials; Wikipedia, "List of islands of Japan" (CC BY-SA 4.0).