There are
1,946 mi
from Fullerton, CA to Dekalb, IL
That's the driving distance. It would take 1 day 10 hours to go from Fullerton, California to Dekalb, Illinois.
The flight distance (direct flight from Fullerton, CA to Dekalb, IL) is 1,675.54 mi.
1,946 mi = 1.61 kms