How to Use the Gas Mileage Calculator
Enter the miles driven since your last full tank and the gallons used to refill to full — the calculator shows your real-world MPG for that fill-up, and tracking this across several fill-ups (as covered in the worked-example guide) gives a more reliable average figure over time.
The Gas Mileage Calculator computes real-world MPG directly from fill-up data — here's what to enter.
Entering miles and gallons
Enter the odometer-tracked miles driven since the last fill-up and the gallons used to refill to full — as covered in the worked-example guide, filling to the same reference point (full) each time is essential for an accurate calculation.
Tracking multiple fill-ups for a reliable average
Running this calculation across several consecutive fill-ups and averaging the results, rather than relying on a single fill-up, smooths out normal variation from differing driving conditions between tanks, giving a more representative real-world MPG figure.