Indiana → Missouri · Interstate 65 / Interstate 70
What does it actually cost to drive from Indianapolis, Indiana, to St. Louis, Missouri? The hard numbers: 437 km (272 miles) of pavement primarily along Interstate 65 / Interstate 70, 4h 10m behind the wheel, and roughly $36.52 in fuel alone — that is 39.7 liters (10.5 gallons) of regular unleaded at a 0.92 USD/liter benchmark. Anyone leaving Indianapolis, the capital of Indiana and home of the Indianapolis 500 motor 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 $187.91. 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.