There are
2,605 mi
from Rockville, MD to Monrovia, CA
That's the driving distance. It would take 1 day 22 hours to go from Rockville, Maryland to Monrovia, California.
The flight distance (direct flight from Rockville, MD to Monrovia, CA) is 2,271.76 mi.
2,605 mi = 4,191.83 kms