Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 19:05 and arrives at Koh Samui Samui International Airport at 20:40.
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 Bangkok is Monday and it would be best to avoid Sunday, as prices are on average 56.41% higher than on Monday. (Average prices, based on 5054778 datapoints.)
We have a lot more statistics for flights PG 185 and between Bangkok and Koh Samui.