Flight Narita International Airport departs from Tokyo Narita International Airport at 09:45 and arrives at Bangkok Suvarnabhumi Airport at 15:15.
The flighttime is about 7h 30m. The distance travelled ("as the bird flies"): 4511 Km. So the average speed is roughly 601 Km.
There is an 2 hour time difference between Tokyo and Bangkok
The best day to arrive at Tokyo is Sunday and it would be best to avoid Friday, as prices are on average 1397.65% higher than on Sunday. (Average prices, based on 157626 datapoints.)
We have a lot more statistics for flights TG 641 and between Tokyo and Bangkok.
