There are
1,840 mi
from Oceanside, CA to St Charles, MO
That's the driving distance. It would take 1 day 8 hours to go from Oceanside, California to St Charles, Missouri.
The flight distance (direct flight from Oceanside, CA to St Charles, MO) is 1,544.71 mi.
1,840 mi = 2,960.96 kms