Gas / Fuel Trip Cost Calculator
Enter the distance, your fuel economy and the price of fuel to see how much a trip will cost. Choose a round trip and add the number of people to split the cost.
How to use this gas / fuel trip cost calculator
- Enter the one-way distance of the trip in miles.
- Choose one way or round trip. A round trip doubles the distance.
- Enter your vehicle fuel economy in miles per gallon, and the price per gallon where you expect to fill up.
- Add tolls or parking if you want them in the total, and the number of people sharing the cost.
- Press Calculate to see the fuel needed, the cost and each share.
How to calculate the fuel cost of a trip
The cost of a trip is the fuel burned times the price of fuel.
- Miles driven = trip distance x 1 (one way) or x 2 (round trip)
- Gallons needed = miles driven / miles per gallon
- Fuel cost = gallons x price per gallon
- Total = fuel cost + tolls and other costs
- Per person = total / number of people
Worked example
A trip is 300 miles each way, so a round trip is 600 miles. The car gets 25 miles per gallon, so it burns 600 / 25 = 24 gallons. At $3.50 per gallon the fuel costs 24 x 3.50 = $84.00. That is $0.14 per mile. Split between 4 people, the share is $21.00 each.
If the road has tolls of $10 each way, enter 20 in the tolls field and the total rises to $104.00, or $26.00 each. For a long drive, try a lower fuel economy figure than the sticker, because highway speed, a loaded trunk and hills all use more fuel.
Assumptions & limits
- The fuel economy figure stays the same for the whole trip. In practice it drops with speed, a heavy load, a roof box, headwinds and stop-and-go traffic.
- The price per gallon is your own input and the calculator does not look up current prices, which vary between stations and states.
- The cost counts fuel and the extras you enter. It does not include wear, maintenance, depreciation or insurance.
- Electric vehicles and hybrids that charge from the grid need the EV vs Gas Cost Calculator.
- For tax purposes, business mileage uses a rate set by the IRS, not the fuel cost.
Frequently asked questions
How do I calculate the gas cost of a trip?
Divide the miles by your miles per gallon to get gallons, then multiply by the price per gallon. For 600 miles at 25 mpg and $3.50 you pay $84.
How do I find my miles per gallon?
Fill the tank, drive, fill it again and divide the miles by the gallons you added. The MPG Calculator on this site does it for you.
Does the cost change with speed?
Yes. Most vehicles use more fuel at high highway speeds, so a lower figure for fuel economy gives a safer estimate.
How do I split the cost of a trip?
Enter the number of people and the calculator divides the total, including tolls, evenly.
Does this include wear and tear?
No. It counts fuel and the extras you enter only.
Can I use it for a diesel vehicle?
Yes. Enter the diesel price per gallon and the diesel fuel economy.
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Last updated: November 2026