There are
2,055 mi
from Walnut Creek, CA to Dekalb, IL
That's the driving distance. It would take 1 day 11 hours to go from Walnut Creek, California to Dekalb, Illinois.
The flight distance (direct flight from Walnut Creek, CA to Dekalb, IL) is 1,775.74 mi.
2,055 mi = 3,307.56 kms