Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 17:50 and arrives at Hanoi Noi Bai International Airport at 19:40.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 593 Km. So the average speed is roughly 323 Km.
The best day to arrive at Bangkok is Saturday and it would be best to avoid Wednesday, as prices are on average 228.66% higher than on Saturday. (Average prices, based on 922088 datapoints.)
We have a lot more statistics for flights TG 564 and between Bangkok and Hanoi.