There are
1,845 mi
from St Charles, MO to Poway, CA
That's the driving distance. It would take 1 day 8 hours to go from St Charles, Missouri to Poway, California.
The flight distance (direct flight from St Charles, MO to Poway, CA) is 1,532.51 mi.
1,845 mi = 2,969.68 kms