There are
2,796 mi
from San Leandro, CA to Gaithersburg, MD
That's the driving distance. It would take 2 days 1 hour to go from San Leandro, California to Gaithersburg, Maryland.
The flight distance (direct flight from San Leandro, CA to Gaithersburg, MD) is 2,409.89 mi.
2,796 mi = 3.22 kms