How to use the gas mileage calculator
- Distance: Distance traveled in miles or kilometers.
- Fuel used: Gallons or liters used over that distance.
- Units: Select the units used for both inputs.
- Select the button and review the result.
Worked example
350 miles using 12 US gallons is about 29.17 mpg.
Method and limitations
Distance ÷ fuel used.
Fill-to-fill measurement over several tanks is usually more representative.
Common questions
Why might another result be different?
Inputs, rounding, policies, rates, and assumptions can differ. Compare like-for-like values and use current official information when a rate or rule can change.
Does NidXee save my entries?
No. The calculation runs in your browser. Reloading or closing the page may clear it.