There are
650 mi
from Gaithersburg, MD to Roswell, GA
That's the driving distance. It would take 12 hours 33 mins to go from Gaithersburg, Maryland to Roswell, Georgia.
The flight distance (direct flight from Gaithersburg, MD to Roswell, GA) is 531.62 mi.
650 mi = 1,046.62 kms