There are
2,636 mi
from Gaithersburg, MD to Manhattan Beach, CA
That's the driving distance. It would take 1 day 23 hours to go from Gaithersburg, Maryland to Manhattan Beach, California.
The flight distance (direct flight from Gaithersburg, MD to Manhattan Beach, CA) is 2,297.16 mi.
2,636 mi = 4,242.09 kms