There are
2,634 mi
from Rockville, MD to Oceanside, CA
That's the driving distance. It would take 1 day 23 hours to go from Rockville, Maryland to Oceanside, California.
The flight distance (direct flight from Rockville, MD to Oceanside, CA) is 2,262.31 mi.
2,634 mi = 4,239.65 kms