There are
2,636 mi
from Gaithersburg, MD to San Clemente, CA
That's the driving distance. It would take 1 day 23 hours to go from Gaithersburg, Maryland to San Clemente, California.
The flight distance (direct flight from Gaithersburg, MD to San Clemente, CA) is 2,266.03 mi.
2,636 mi = 4,241.90 kms