There are
1,818 mi
from St Charles, MO to Fullerton, CA
That's the driving distance. It would take 1 day 7 hours to go from St Charles, Missouri to Fullerton, California.
The flight distance (direct flight from St Charles, MO to Fullerton, CA) is 1,557.03 mi.
1,818 mi = 2,926.49 kms