MPG Calculator — Fuel Economy
Calculate MPG from miles and gallons, then see your annual fuel cost and cost per mile with your own fuel price.
Fuel math runs on your device — your mileage and fuel prices stay privateTry: Miles driven=300, Gallons used=10, Miles per year=12000, Fuel price=3.5 → 30.0 MPG, $1,400.00, $0.12
How to use
MPG (miles per gallon) is simply the miles you drove divided by the gallons you used. Reset your trip odometer, fill the tank, drive a while, then divide miles by gallons at the next fill-up. The calculator also prices your annual fuel and cost per mile using your fuel price.
FAQ
Is a higher MPG always better?
For fuel cost and emissions, yes — higher MPG means fewer gallons per mile. But total savings also depend on how many miles you drive and the price you paid for the car.
Why does my car show lower MPG than the EPA rating?
EPA figures are lab estimates. Real driving — cold weather, short trips, highway speeds, heavy loads, and tire pressure — typically lands 10–20% below the sticker.
Do US and UK MPG mean the same thing?
No. The UK (imperial) gallon is about 20% larger, so an identical car shows a higher number in UK MPG than in US MPG. Always check which one a source uses.