There are
325 mi
from Decatur, IL to Oshkosh, WI
That's the driving distance. It would take 6 hours 20 mins to go from Decatur, Illinois to Oshkosh, Wisconsin.
The flight distance (direct flight from Decatur, IL to Oshkosh, WI) is 289.89 mi.
325 mi = 523.20 kms