Flight Leonardo da Vinci–Fiumicino Airport departs from Rome Leonardo da Vinci–Fiumicino Airport at 10:20 and arrives at Miami International Airport at 17:15.
The flighttime is about 12h 55m. The distance travelled ("as the bird flies"): 10330 Km. So the average speed is roughly 800 Km.
There is an 6 hour time difference between Rome and Miami