Fun Fact: Thailand's Second or Third Largest Island?

You will read both that Koh Samui is 'Thailand's second-largest island' and 'third-largest'. Both come from reputable-looking sources. The discrepancy is about the list used: Phuket (roughly 543 km², connected to the mainland by bridge) is always first; Koh Chang (roughly 210-217 km²) and Koh Samui (figures vary between about 229 and 247 km²) are close, and some lists count differently or use different measured areas. The safe factual statement: Samui is one of Thailand's three largest islands, with an area of roughly 230-250 km² depending on the source, about 25 km long and 21 km wide, and the largest island in the Chumphon Archipelago in the Gulf of Thailand.

Details

You will read both that Koh Samui is 'Thailand's second-largest island' and 'third-largest'. Both come from reputable-looking sources. The discrepancy is about the list used: Phuket (roughly 543 km², connected to the mainland by bridge) is always first; Koh Chang (roughly 210-217 km²) and Koh Samui (figures vary between about 229 and 247 km²) are close, and some lists count differently or use different measured areas. The safe factual statement: Samui is one of Thailand's three largest islands, with an area of roughly 230-250 km² depending on the source, about 25 km long and 21 km wide, and the largest island in the Chumphon Archipelago in the Gulf of Thailand.

Highlights

• Samui is one of Thailand's three largest islands - sources disagree on 2nd vs 3rd
• Area figures vary by source: about 229-247 km²
• Roughly 25 km long by 21 km wide
• Largest island of the Chumphon Archipelago / Ang Thong group area

Local tips

• When a fact varies this much between sources, it usually does not matter for your trip - but it is a good lesson in checking travel claims

Frequently asked questions

Is Koh Samui the second biggest island in Thailand?

It depends on the source. Some say second (after Phuket), others third (after Phuket and Koh Chang). Area estimates for Samui range from about 229 to 247 km².