There are
534 mi
from Sioux Falls, SD to Dekalb, IL
That's the driving distance. It would take 9 hours 40 mins to go from Sioux Falls, South Dakota to Dekalb, Illinois.
The flight distance (direct flight from Sioux Falls, SD to Dekalb, IL) is 418.48 mi.
534 mi = 858.84 kms