3 Ways to Calculate Fuel Consumption
· Divide mileage by fuel usage to see your car's fuel consumption. This tells you how many miles you drove per gallon of gas. For example, if you drove 335 miles before refueling, and you filled your car up with 12 gallons of gas, your fuel consumption was 27.9 miles per gallon, or mpg (335 miles / 12 gallon = 27.9 mpg).