Flight Sydney Airport departs from Sydney Sydney Airport at 10:35 and arrives at Perth Perth Airport at 13:40.
The flighttime is about 5h 05m. The distance travelled ("as the bird flies"): 3917 Km. So the average speed is roughly 771 Km.
There is an 2 hour time difference between Sydney and Perth
The best day to arrive at Sydney is Saturday and it would be best to avoid Wednesday, as prices are on average 169.88% higher than on Saturday. (Average prices, based on 7263159 datapoints.)
We have a lot more statistics for flights QF 645 and between Sydney and Perth.
IDR