How it works
How to calculate it
The calculator applies the values you enter to this formula:
Gallons = miles ÷ MPG; fuel cost = gallons × price per gallon.
How to use this calculator
- Enter total distance.
- Use realistic average MPG.
- Enter the fuel grade and route price you expect to pay.
Worked example
Driving 1,000 miles at 28 MPG uses about 35.7 gallons and costs $125 at $3.50/gal.
Important assumptions
- MPG is an average for the trip.
- Idling, detours, towing, and elevation can change fuel use.
- Tolls, parking, and vehicle wear are excluded.
Common mistakes to avoid
- Using one-way distance for a round trip.
- Using dashboard MPG from an unusually efficient drive.
- Leaving out idling, towing, or detours.
Method reviewed June 10, 2026. Prices and rates are user-provided defaults and should be replaced with local values.