There are
1,952 mi
from Tustin, CA to Dekalb, IL
That's the driving distance. It would take 1 day 10 hours to go from Tustin, California to Dekalb, Illinois.
The flight distance (direct flight from Tustin, CA to Dekalb, IL) is 1,674.59 mi.
1,952 mi = 3,140.71 kms