There are
1,025 mi
from Thornton, CO to Waukesha, WI
That's the driving distance. It would take 18 hours 9 mins to go from Thornton, Colorado to Waukesha, Wisconsin.
The flight distance (direct flight from Thornton, CO to Waukesha, WI) is 892.21 mi.
1,025 mi = 1.61 kms