There are
2,576 mi
from Gaithersburg, MD to Rancho Cucamonga, CA
That's the driving distance. It would take 1 day 21 hours to go from Gaithersburg, Maryland to Rancho Cucamonga, California.
The flight distance (direct flight from Gaithersburg, MD to Rancho Cucamonga, CA) is 2,247.93 mi.
2,576 mi = 4,145.60 kms