Chiang-mai to Koh-samui

A direct flight from Chiang Mai to Koh Samui takes around 1 hour and 45 minutes. Flights depart from Chiang Mai International Airport, about 3 km southwest of the city center, and arrive at Koh Samui International Airport (USM)—the only operator to run a direct service in Bangkok Airways. The fares typically range from 3,400 THB to 4800 THB, depending upon the operator and time of booking.

You will have to travel via bangkok because there is no direct option. You can take the bus from Chiang Mai to bangkok and then another bus from bangkok to Surathani; from there, you can take a ferry to Koh Samui.

Chiang Mai to Bangkok by Bus
 Buses depart daily from Chiang Mai Bus Terminal 3 and Chiang Mai Bus Arcade 2 and reach Mochit bus terminal in Bangkok.

The journey from Chiang Mai to Bangkok by bus typically takes 11 to 15 hours, depending on factors such as traffic, road conditions, and the type of bus. Twelve buses run daily from 7:30 a.m. to 9:30 p.m.

Bangkok to Surathani by Bus
The journey to Surathani usually takes 8-10 hours. The fares usually range from approximately 700 to 1500 THB, depending on the type of bus and booking dates. You can take a bus from the southern terminal in bangkok to Surathani.

Ferry from Donsak Pier to Koh Samui
To reach Koh Samui from Donsak Pier by ferry, head to Donsak Pier near Surat Thani. Several ferry operators, including Seatran, Raja, and Lomprayah, offer frequent daily services. The ferry ride takes approximately 1.5 to 2 hours, and tickets typically cost between 150 to 300 THB

Chiang Mai to Bangkok by Train
The journey from Chiang Mai to Bangkok takes 11 to 14 hours. The train departs from the Chaing Mai railway station and moves to Bangkok's Hua Lamphong railway station. The journey usually takes 12-15 hours. The best way to go from Chiang Mai to Bangkok is by taking a night train with a first—or second-class sleeper.

 The beds on Thai trains are very comfortable and come with curtains for privacy during your long journey. Trains usually run throughout the day, with the first starting at 6:30 AM and an overnight train at 5 in the evening. 

The fares depend upon factors like the type of train and seating options.

First Class: Approximately 1,500 to 2,500 THB
Second Class (Air-conditioned): Around 800 to 1,500 THB
Second Class (Fan-cooled): Approximately 600 to 1,200 THB

Bangkok to Surathani by Train
You can take a train from Bangkok's Hua Lamphong Train Station to Surat Thani, which takes around 11 to 15 hours, depending upon the traffic. Ten trains are daily from Bangkok to Surat Thani, departing between 7 am and run till 10 pm. It's best to take an air-conditioned sleeper train to save on a hotel for the night and have a more comfortable journey. 

Ferry from Donsak Pier to Koh Samui
To reach Koh Samui from Donsak Pier by ferry, head to Donsak Pier near Surat Thani. Several ferry operators, including Seatran, Raja, and Lomprayah, offer frequent daily services. The ferry ride takes approximately 1.5 to 2 hours, and tickets typically cost between 150 to 300 THB