Flight Keflavík International Airport departs from Reykjavik Keflavík International Airport at 19:45 and arrives at Washington Ronald Reagan National Airport at 22:10.
The flighttime is about 7h 25m. The distance travelled ("as the bird flies"): 6205 Km. So the average speed is roughly 837 Km.
There is an 5 hour time difference between Reykjavik and Washington