There are
2,968 mi
from Danbury, CT to San Mateo, CA
That's the driving distance. It would take 2 days 4 hours to go from Danbury, Connecticut to San Mateo, California.
The flight distance (direct flight from Danbury, CT to San Mateo, CA) is 2,585.21 mi.
2,968 mi = 3.22 kms