A car's window-sticker MPG comes from a standardized EPA lab test — controlled speed, controlled temperature, no hills, no traffic, no AC blasting. Your actual mileage depends on how and where you actually drive, which is why it's completely normal for it to come out lower (or higher) than the official number.
MPG calculator, from your own numbers
Enter the distance you drove and how much fuel it took, and this calculator computes your real-world fuel economy — the number that actually reflects your car, your route, and your driving style.
How to calculate MPG accurately
Fill the tank completely, reset your trip odometer, drive normally, then fill up completely again — the miles driven divided by the gallons it took to refill gives you an accurate reading for that tank.
Cost per mile calculator, factoring in your fuel price
Add your price per gallon to see cost per mile alongside MPG — useful for comparing what a specific trip or commute actually costs, not just how efficient the car is in the abstract.
