Place comparison

Green Island compared with Koh Samui: area, population and density

Koh Samui has about fifteen times Green Island’s land area and a far larger resident count, while their approximate average densities are surprisingly close.

Place A Grouped by country or region Place B Grouped by country or region

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

The guide below belongs to this pair: Green Island and Koh Samui. Change the selector above and the page follows, so the reading always matches the tool.

Direct answer

How different are Green Island and Koh Samui?

Green Island covers 15.1 km² (5.83 sq mi); Green Island's area is about 6.6% of Koh Samui's. Its reported population is 4,327; Green Island's population is about 6.2% of Koh Samui's. By average density, Green Island's population density is about 93.4% of Koh Samui's.

Area difference

Green Island's area is about 6.6% of Koh Samui's 15.1 km² (5.83 sq mi) · 227 km² (87.6 sq mi)

Population difference

Green Island's population is about 6.2% of Koh Samui's 4,327 · 69,689

Density difference

Green Island's population density is about 93.4% of Koh Samui's 286.7 /km² (743 /sq mi) · 307 /km² (795 /sq mi)

Full data and sources for each place: Green Island area & population, Koh Samui area & population

Straight-line distance between geometric centres: about 2717 km; time difference: 1 hour.

On a familiar scale

Green Island ≈ 26% of Manhattan (reference rung) 3,488 m² of land per resident
Koh Samui ≈ 1.43 × Washington, D.C. (reference rung) 3,257 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

The near-density result is only a first-order comparison because Koh Samui population includes 18 surrounding municipal islands.

Geography and shape

Green Island is a compact volcanic island off Taiwan’s southeast coast. Koh Samui is a much larger Gulf of Thailand island with a wider road and settlement network. Putting both outlines on one scale makes the fifteen-fold area gap immediately visible.

Population context

The reported population ratio broadly follows the area ratio, which produces similar rough densities. Green Island uses township registered population; Koh Samui uses a municipal total whose geographic reach is wider than its main-island outline.

Boundaries and definitions

Green Island pairs a physical island with its nearly coextensive township population. Koh Samui pairs its physical island with a municipality covering the main island and 18 others. Area comparison is clean; density needs the displayed scope note.

Green Island: Physical Green Island area paired with the registered population of Green Island Township at year-end 2025. The township and main island are nearly coextensive, but the population remains an administrative count.

Koh Samui: Area is for Koh Samui main island. Population is the 2024 Ko Samui City Municipality total, whose 252 km² administration includes the 227 km² main island and 18 surrounding islands; density is therefore approximate for the main island.

In-depth guide

How should Green Island and Koh Samui be understood in context?

Green Island and Koh Samui offer a clean visual contrast between a compact Taiwanese island and a much larger Thai resort island. The roughly fifteenfold land gap is more informative than either number alone.

Two physical islands on one scale

Both outlines refer to physical islands, so the area comparison is straightforward. Koh Samui’s main island is about fifteen times Green Island by land.

That difference changes route choices, settlement spread and the practical meaning of staying in one part of the island. It does not by itself determine travel time.

A surprisingly similar rough density

Reported population increases by a broadly similar multiple, creating close average densities. The resemblance is useful as a prompt, not a claim that the two islands feel alike.

Hotels, visitors, roads, terrain and where residents cluster are all absent from the calculation.

Population boundaries are not equally clean

Green Island Township nearly matches the island and provides the registered total. Ko Samui Municipality includes eighteen additional islands beyond the main-island outline.

Readers can trust the area ratio directly and should treat the density comparison as approximate until a main-island-only population becomes available.

Questions people ask

About this geographic comparison

Which is bigger, Green Island or Koh Samui?

Koh Samui is bigger, with a land area about 15× that of Green Island (Green Island 15.1 vs Koh Samui 227 km², or 5.83 sq mi vs 87.6 sq mi).

How big is Green Island compared to Koh Samui?

Koh Samui has 227 km² (87.6 sq mi) and Green Island has 15.1 km² (5.83 sq mi): the ratio is 15×. Conversely, Green Island has 6.6% of Koh Samui's area.

Does Green Island or Koh Samui have more people?

Koh Samui has 69,689 people (2024-12-31), versus 4,327 in Green Island (2025-12-31): 16.1×. In reverse, Green Island has 6.2% of Koh Samui's population. Green Island is 6.6% the size of Koh Samui — 15.1 km² vs 227 km² (5.83 sq mi vs 87.6 sq mi). Population is 6.2% as high; average density is 93.4% as high. Each side’s scope and reference date are set out under “Boundaries and definitions” on this page.

Is Green Island bigger than Koh Samui?

No. Koh Samui is bigger, with a land area about 15× that of Green Island (Green Island 15.1 vs Koh Samui 227 km², or 5.83 sq mi vs 87.6 sq mi). The area difference is 211.9 km². Koh Samui has 227 km² (87.6 sq mi) and Green Island has 15.1 km² (5.83 sq mi): the ratio is 15×. Conversely, Green Island has 6.6% of Koh Samui's area.

How many Green Islands fit inside Koh Samui?

By land area, the 227 km² Koh Samui main island is about fifteen Green Islands.

Are both population figures island-only counts?

Not exactly. Green Island uses township population, while Koh Samui’s municipality includes 18 surrounding islands.

Can density predict the travel experience?

No. Seasonal visitors, roads, resort concentration and terrain are outside this resident-and-land calculation.

Sources

Outline data: