How much money on gas would you spend traveling from Kansas City MO to St Louis MO?

The distance between Kansas City, MO, and St. Louis, MO, is approximately 240 miles. Assuming you are driving a car that gets 30 miles per gallon (MPG), you would need approximately 8 gallons of gas for the round trip. At current gas prices of around $3.50 per gallon, the cost of gas for the trip would be approximately $28.