Koh Samui is a Gulf of Thailand island in Surat Thani province, ringed by beaches, with a green mountainous interior and a ring road that lets you reach almost anywhere in under an hour. It is easy to enjoy and easy to waste, because the best things on it are mostly on the water or off the main roads. This guide lays out what to book, how to move around and how to fit the highlights into the time you have.
What to book ahead
Book the island day trips first, because they set the shape of your week. Ang Thong National Marine Park is the headline: a full day among 42 limestone islands with kayaking, snorkelling and a viewpoint hike. Koh Tao and Koh Nang Yuan are the second big trip, with a speedboat run and a famous sandbar. For something shorter, Pig Island and Koh Tan is an easy half day, and the Koh Phangan junk boat cruise adds a slow sail and a sunset. Choose free-cancellation options, because weather decides whether boats sail. After the trips, the only things that need advance booking are the Muay Thai fight night, a cooking class and, if you want it, an ethical elephant sanctuary visit.
When to go
The dry months from roughly December to April are the easiest for boat trips and beach days. The Gulf's wetter period runs from roughly October to December, with more rain and swell, so some boat days are cancelled or rerouted, and in some years Ang Thong has been closed for part of that period. If you travel in these months, plan indoor and inland activities such as the jungle safari, the temples tour, a cooking class and the spa, and keep one spare day for a boat trip that gets moved.
Getting around
Samui has no train, no metro and no ride-hailing network you can rely on everywhere. Most visitors use hotel transfers, taxis, shared songthaews along the ring road, rental scooters or a rental car. Taxis are convenient but not cheap, so agree the fare before you set off. Scooters are popular but accident rates are high, and many travel policies exclude riders without the right licence, so think carefully. For island trips and tours, pickup from your hotel is normally included, which solves most of the transport question.
How many days
Three days is enough to do one big boat trip, the Big Buddha and island highlights and a beach day. Five days lets you add Koh Tao or Ang Thong on separate days, a jungle safari, a cooking class and a spa afternoon. A week is comfortable, and the right length if you also want a rest day for each big trip. Samui also works as a base for Koh Phangan and Koh Tao day trips, so you do not need to move hotels.
How the headline sights fit
The north-east coast, around Bophut and Choeng Mon, holds the Big Buddha, Fisherman's Village and the airport. Chaweng, the east-coast beach, is the busiest area for shops, restaurants and nightlife. Lamai, further south, is calmer. The interior has the waterfalls and the jeep safari routes, and the west and south coasts are quieter, with the best sunsets. A highlights tour is a good way to see the layout in half a day before you pick where to spend the rest.
A simple plan
On day one, rest and visit a beach. On day two, take the Big Buddha and island highlights tour, then a sunset dinner. On day three, go to Ang Thong. On day four, take an easier day with the cooking class or the elephant sanctuary. On day five, take Koh Tao or Pig Island. Add the zipline or the jungle safari if you want more adventure, and fit a Muay Thai night on any free evening.
What to pack and know
Bring reef-safe sunscreen, a light rain jacket for the wet months, a scarf or sarong for temples, closed shoes for hikes and safaris, a dry bag and some cash for park and island fees. Cover shoulders and knees at temples, and treat elephants and wildlife with care. Check each booking for what is included, particularly park fees, lunch and pickups, and read the weather policy before you pay.