Place comparison

Koh Samui compared with Penghu: area, population and density

Koh Samui main island has substantially more land than the whole Penghu County archipelago, while Penghu reports more registered residents.

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: Koh Samui and Penghu County. Change the selector above and the page follows, so the reading always matches the tool.

Direct answer

How different are Koh Samui and Penghu County?

Koh Samui covers 227 km² (87.6 sq mi); Koh Samui's area is 1.77 times Penghu County's. Its reported population is 69,689; Koh Samui's population is about 64.6% of Penghu County's. By average density, Koh Samui's population density is about 36.4% of Penghu County's.

Area difference

Koh Samui's area is 1.77 times Penghu County's 227 km² (87.6 sq mi) · 128 km² (49.4 sq mi)

Population difference

Koh Samui's population is about 64.6% of Penghu County's 69,689 · 107,901

Density difference

Koh Samui's population density is about 36.4% of Penghu County's 307 /km² (795 /sq mi) · 843.2 /km² (2,184 /sq mi)

Full data and sources for each place: Koh Samui area & population, Penghu County area & population

Straight-line distance between geometric centres: about 2602 km; time difference: 1 hour.

On a familiar scale

Koh Samui ≈ 1.43 × Washington, D.C. (reference rung) 3,257 m² of land per resident
Penghu County ≈ 81% of Washington, D.C. (reference rung) 1,186 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

This pairs one Thai island with a 90-island Taiwanese county. Koh Samui population includes 18 surrounding municipal islands, so its density is approximate.

Geography and shape

Koh Samui is one continuous main island in the Gulf of Thailand. Penghu is a county archipelago whose smaller total land is split across 90 inventoried islands. Similar tourism labels therefore hide very different coastline and transport structures.

Population context

Penghu reports more registered residents despite having less land. The displayed Koh Samui density must be read cautiously because its municipal population also covers 18 surrounding islands that are not included in the main-island outline.

Boundaries and definitions

Koh Samui area is the 227 km² main island. Penghu area and population cover the entire county archipelago. The comparison is useful for land scale, while the Koh Samui density is explicitly an approximation.

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.

Penghu County: The full Penghu County archipelago: 90 islands in the county inventory. Population is the registered year-end total; the area figure is the current official inventory accessed September 4, 2026.

In-depth guide

How should Koh Samui and Penghu County be understood in context?

Koh Samui and Penghu are both familiar island destinations, but they are not the same kind of geographic object. One is a physical main island; the other is a Taiwanese county spread across ninety islands.

One island versus a county archipelago

Koh Samui’s 227 km² forms one main island with a continuous road network. Penghu’s smaller county total is distributed across inhabited and uninhabited islands.

A land ratio therefore cannot predict ferry reliance, bridge connections or the distance between accommodation and attractions.

Population reveals a different ranking

Penghu has less land but reports more registered residents. This reverses the first impression created by physical size and shows why island comparisons should include population.

Seasonal visitors are absent from both resident totals. A busy holiday period can feel much denser than the displayed annual administrative baseline.

Why Koh Samui density is approximate

The municipality publishes a current population, but its jurisdiction includes the main island and eighteen surrounding islands. The main-island area and municipal population are not perfectly aligned.

Atlas keeps the better-recognised physical island outline and labels the density limitation directly. The land-area comparison remains aligned and reliable.

Questions people ask

About this geographic comparison

Which is bigger, Koh Samui or Penghu County?

Koh Samui is bigger, with a land area about 1.77× that of Penghu County (Koh Samui 227 vs Penghu County 128 km², or 87.6 sq mi vs 49.4 sq mi).

How big is Koh Samui compared to Penghu County?

Koh Samui has 227 km² (87.6 sq mi) and Penghu County has 128 km² (49.4 sq mi): the ratio is 1.77×. Conversely, Penghu County has 56.4% of Koh Samui's area.

Does Koh Samui or Penghu County have more people?

Penghu County has 107,901 people (2024-12-31), versus 69,689 in Koh Samui (2024-12-31): 1.55×. In reverse, Koh Samui has 64.6% of Penghu County's population. Koh Samui is 1.77× the size of Penghu County — 227 km² vs 128 km² (87.6 sq mi vs 49.4 sq mi). Population is 64.6% as high; average density is 36.4% as high. Each side’s scope and reference date are set out under “Boundaries and definitions” on this page.

Is Koh Samui bigger than Penghu County?

Yes. Koh Samui is bigger, with a land area about 1.77× that of Penghu County (Koh Samui 227 vs Penghu County 128 km², or 87.6 sq mi vs 49.4 sq mi). The area difference is 99 km². Koh Samui has 227 km² (87.6 sq mi) and Penghu County has 128 km² (49.4 sq mi): the ratio is 1.77×. Conversely, Penghu County has 56.4% of Koh Samui's area.

How many times does Penghu County fit into Koh Samui?

By land area, Penghu County fits into Koh Samui about 1.77 times (227 km² vs 128 km², or 87.6 sq mi vs 49.4 sq mi). It is an area ratio, not a jigsaw fit: coastlines and shapes differ, which the outlines on this page show at one scale.

Which is larger, Koh Samui or Penghu?

Koh Samui main island has more land than all 90 islands in Penghu County combined.

Does Penghu mean Penghu Main Island?

No. It is the complete county archipelago in the official inventory.

Is Koh Samui density exact?

No. The official population is municipal and includes 18 surrounding islands, so the main-island density is approximate.

Sources

Outline data: