Flight Samui International Airport departs from Koh Samui Samui International Airport at 14:30 and arrives at Bangkok Suvarnabhumi Airport at 16:05.
The flighttime is about 1h 35m. The distance travelled ("as the bird flies"): 113 Km. So the average speed is roughly 71 Km.
The best day to arrive at Koh Samui is Wednesday and it would be best to avoid Friday, as prices are on average 305.27% higher than on Wednesday. (Average prices, based on 1275058 datapoints.)
We have a lot more statistics for flights PG 138 and between Koh Samui and Bangkok.