There are
2,768 mi
from Allentown, PA to Seatac, WA
That's the driving distance. It would take 2 days 1 hour to go from Allentown, Pennsylvania to Seatac, Washington.
The flight distance (direct flight from Allentown, PA to Seatac, WA) is 2,337.18 mi.
2,768 mi = 3.22 kms