Kansas is a large state (400+ miles wide), so drive time to Chicago varies significantly by starting point.
~500 miles, 8.5–10.5 hours via I-70 East to I-65 North (through Indianapolis) or I-35 North to I-80 East (through Des Moines). The I-70 route is slightly shorter; I-80 often faster with higher speed limits.
~650 miles, 10.5–12 hours via I-35 North to I-80 East (through KC, Des Moines) or US-54/US-400 to I-35.
~750–800 miles, 11.5–13 hours via US-50/US-400 to I-35/I-70/I-80 corridors.
Use real-time traffic apps (Google Maps, Waze). Avoid Chicago rush hours (7–9 AM, 4–6 PM). Winter weather on I-80 across Nebraska/Iowa can be severe. Fuel in Kansas/NE is often cheaper than IL.