Find your car's real miles per gallon from your last fill-up. Enter the distance you drove and the fuel you used — get MPG, L/100km, km/L and your cost per mile, live.
✓ Formula shown openly • ✓ Reviewed October 2026 • ✓ Free — no sign-up • ✓ Nothing you enter is stored
MPG Calculator
Formula: MPG = Distance ÷ Fuel Used • Live results — nothing is stored.
MPG (miles per gallon) is simply the distance you drove divided by the fuel it took: MPG = Distance ÷ Gallons. The most accurate method is tank-to-tank: fill the tank completely, reset your trip odometer, drive as normal, then fill up again and divide the miles driven by the gallons the second fill took.
You drove 360 miles and the refill took 12 gallons: 360 ÷ 12 = 30.00 MPG. That equals 7.84 L/100km or 12.75 km/L. At $3.50 a gallon, your fuel cost per mile is $3.50 ÷ 30 = about $0.12 per mile, and the fill-up cost $42.00.
A sudden drop of 3–5 MPG versus your usual figure is an early warning sign — check tire pressure, air filter and driving style first. Track yours with our gas mileage calculator, then turn MPG into money with the fuel cost calculator.
EPA figures come from lab cycles. Real traffic, cold weather, hills, roof cargo and aggressive acceleration typically cost 10–15%. Your tank-to-tank number is the honest one.
Divide 235.215 by your MPG. Example: 30 MPG → 235.215 ÷ 30 = 7.84 L/100km. This calculator shows the conversion automatically.
You can, but it is less accurate because you cannot be sure exactly how much fuel was used. Full-tank to full-tank is the reliable method.
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