There are
1,982 mi
from St Charles, MO to Vacaville, CA
That's the driving distance. It would take 1 day 10 hours to go from St Charles, Missouri to Vacaville, California.
The flight distance (direct flight from St Charles, MO to Vacaville, CA) is 1,692.09 mi.
1,982 mi = 3,189.15 kms