Fuel Cost Calculator
Work out the fuel cost and gallons for a single trip from distance, fuel economy and gas price.
How it works
Gallons = distance ÷ MPG · Fuel cost = gallons × gas price
Divide the trip distance by your fuel economy to get the gallons burned, then multiply by the pump price. This focuses on one trip in one car; if you are carpooling and want each person’s share, the fuel trip cost calculator splits the same total between riders.
Worked example
A 300-mile trip in a car that gets 28 MPG needs about 10.71 gallons. At $3.50 a gallon that is $37.50 one way, or $75.00 round trip — roughly $0.125 per mile.
Frequently asked questions
Does highway or city driving change this?
Yes — use the MPG that matches the trip. Highway driving usually beats the combined rating, while city stop-and-go and heavy loads drag it down, so a long road trip often costs less per mile than errands.
How do I split fuel cost with passengers?
Divide the total fuel cost by the number of people sharing the ride. The fuel trip cost calculator does this directly for carpools and shared road trips.
Why estimate gallons, not just cost?
Knowing the gallons tells you how many fill-ups a trip needs and whether your tank range covers the distance between stations — useful for planning stops on a long drive.
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This calculator is for educational purposes. Double-check important results before acting on them.