There are
1,825 mi
from St Charles, MO to Tustin, CA
That's the driving distance. It would take 1 day 7 hours to go from St Charles, Missouri to Tustin, California.
The flight distance (direct flight from St Charles, MO to Tustin, CA) is 1,554.75 mi.
1,825 mi = 2,936.39 kms