Gas Mileage Calculator
Fuel economy —
Cost per mile —
Measure from a full tank to a full tank for the most accurate reading — resetting the trip odometer and refilling completely each time cancels out any error from not filling the tank exactly the same way.
Free gas mileage (MPG) calculator — enter distance driven and fuel used to see your real-world fuel economy and cost per mile.
How it works
- Enter the distance you drove and the fuel you used to drive it
- Optionally enter your price per gallon
- See your actual MPG and cost per mile instantly
Frequently asked questions
What's the most accurate way to measure my own MPG?
Fill the tank completely, reset your trip odometer, drive normally, then fill up completely again and note the miles driven and gallons it took to refill — that's your real-world MPG for that tank.
Why does my calculated MPG differ from the window sticker?
EPA ratings are measured under standardized lab conditions. Real-world MPG varies with driving style, terrain, weather, tire pressure, and load — it's normal for it to differ from the official rating.
Related tools
From the blog
Update history
- 2026-09-02 Launched: gas mileage (MPG) calculator from real driving data, with optional cost-per-mile. Entirely client-side.