There are
1,610 mi
from Gaithersburg, MD to San Antonio, TX
That's the driving distance. It would take 1 day 4 hours to go from Gaithersburg, Maryland to San Antonio, Texas.
The flight distance (direct flight from Gaithersburg, MD to San Antonio, TX) is 1,383.68 mi.
1,610 mi = 2,591.36 kms