There are
2,764 mi
from Antioch, CA to Gaithersburg, MD
That's the driving distance. It would take 2 days to go from Antioch, California to Gaithersburg, Maryland.
The flight distance (direct flight from Antioch, CA to Gaithersburg, MD) is 2,386.12 mi.
2,764 mi = 4,448.14 kms