There are
877 mi
from Mckinney, TX to Dekalb, IL
That's the driving distance. It would take 16 hours 16 mins to go from Mckinney, Texas to Dekalb, Illinois.
The flight distance (direct flight from Mckinney, TX to Dekalb, IL) is 741.36 mi.
877 mi = 1,410.67 kms