Kentucky → Missouri · Interstate 65 / Interstate 64
What does it actually cost to drive from Louisville, Kentucky, to St. Louis, Missouri? The hard numbers: 459 km (285 miles) of pavement primarily along Interstate 65 / Interstate 64, 4h 22m behind the wheel, and roughly $38.36 in fuel alone — that is 41.7 liters (11.0 gallons) of regular unleaded at a 0.92 USD/liter benchmark. Anyone leaving Louisville, the largest city in Kentucky and home of the Kentucky Derby horse race, typically carries samples, signed proposals, or service equipment to deliver in St. Louis, the historic Gateway to the West and a major Mississippi River freight port, and aims to be home the same evening. It is worth confirming whether the haul fits inside your daily hours-of-service window or whether an overnight at a midpoint hotel makes more sense. Applying the IRS standard mileage rate (2025) mileage rate of $0.43/km ($0.69/mile), the gross outbound reimbursement settles at $197.37. Attach the visit purpose, client name, and plate number to the Clara receipt so the journal entry lands directly in the business-travel expense account.