There are
1,985 mi
from Vacaville, CA to St Charles, MO
That's the driving distance. It would take 1 day 10 hours to go from Vacaville, California to St Charles, Missouri.
The flight distance (direct flight from Vacaville, CA to St Charles, MO) is 1,692.09 mi.
1,985 mi = 1.61 kms