Flight Samui International Airport departs from Koh Samui Samui International Airport at 17:40 and arrives at Bangkok Suvarnabhumi Airport at 18:55.
The flighttime is about 1h 15m. The distance travelled ("as the bird flies"): 113 Km. So the average speed is roughly 90 Km.
The best day to arrive at Koh Samui is Wednesday and it would be best to avoid Thursday, as prices are on average 36.91% higher than on Wednesday. (Average prices, based on 1276846 datapoints.)
We have a lot more statistics for flights PG 164 and between Koh Samui and Bangkok.