Missouri → Missouri · Interstate 70 / Interstate 35
The drive from Kansas City, Missouri, to St. Louis, Missouri, covers about 452 km (281 miles) along Interstate 70 / Interstate 35, with an estimated travel time of 4h 18m in normal traffic conditions. Kansas City is the Missouri jazz and barbecue capital straddling the state line and a key Midwest rail hub, while St. Louis stands out as the historic Gateway to the West and a major Mississippi River freight port. Sales reps, consultants, real-estate agents and field service professionals who run this route regularly typically depart at sunrise to clear the urban congestion before rush hour and arrive in time for scheduled morning meetings. It also pays to scout two or three reliable fuel-and-rest stops along the way before departure. Assuming average fuel economy of about 26 mpg on regular unleaded, the trip burns roughly 41.1 liters (10.9 gallons), costing about $37.81 at typical pump prices. For mileage reimbursement, applying the IRS standard mileage rate (2025) of $0.43/km ($0.69/mile) yields a one-way payout of $194.36. Keep the trip log, business purpose, odometer readings, and exact route documented in your Clara receipt for IRS compliance and internal audit defensibility.