There are
2,403 mi
from South San Francisco, CA to Lexington, KY
That's the driving distance. It would take 1 day 18 hours to go from South San Francisco, California to Lexington, Kentucky.
The flight distance (direct flight from South San Francisco, CA to Lexington, KY) is 2,053.63 mi.
2,403 mi = 3,867.78 kms