There are
1,820 mi
from Irvine, CA to Festus, MO
That's the driving distance. It would take 1 day 7 hours to go from Irvine, California to Festus, Missouri.
The flight distance (direct flight from Irvine, CA to Festus, MO) is 1,558.18 mi.
1,820 mi = 2,928.50 kms