There are
1,955 mi
from Downey, CA to Dekalb, IL
That's the driving distance. It would take 1 day 10 hours to go from Downey, California to Dekalb, Illinois.
The flight distance (direct flight from Downey, CA to Dekalb, IL) is 1,683.83 mi.
1,955 mi = 1.61 kms