There are
953 mi
from Gaithersburg, MD to Panama City Beach, FL
That's the driving distance. It would take 18 hours 38 mins to go from Gaithersburg, Maryland to Panama City Beach, Florida.
The flight distance (direct flight from Gaithersburg, MD to Panama City Beach, FL) is 788.42 mi.
953 mi = 1,533.57 kms