There are
402 mi
from Warwick, RI to Gaithersburg, MD
That's the driving distance. It would take 8 hours 23 mins to go from Warwick, Rhode Island to Gaithersburg, Maryland.
The flight distance (direct flight from Warwick, RI to Gaithersburg, MD) is 351.74 mi.
402 mi = 647.57 kms