Fuel Cost Calculator
This fuel cost calculator turns a trip into a dollar figure. Enter the distance, your vehicle's MPG, and the price of gas, and you'll see the total fuel cost, the gallons you'll burn, and the cost per mile. Flip on round trip for there-and-back, or split the bill between riders for a fair carpool number. It's free, private, and a quick way to budget any drive before you go.
- Total cost
- Gallons used
- Cost per mile
- Round trip
- Split the bill
Last updated June 17, 2026 Miles, MPG, and US dollars Reviewed by the Calcowa team
Enter a distance, an MPG above zero, and a gas price.
Figures use US miles, MPG, and dollars per gallon. Gas prices change often, so use the price you'll pay at the pump.
How do you calculate fuel cost?
Fuel cost comes down to three numbers: how far you're going, how many miles your car gets per gallon, and what a gallon costs. First you divide the distance by the MPG, which tells you the gallons the trip needs. Then you multiply those gallons by the price per gallon to get the total. This calculator runs both steps for you, and it adds the cost per mile so you can compare drives, plus a round-trip option and a split so a carpool settles up fairly. Everything updates the moment you change a number, and it all stays in your browser.
Budgeting a drive, step by step
Here's the quick routine for any trip you're planning:
- 1
Enter the distanceType how far you're driving, one way, in miles.
- 2
Add MPG and pricePut in your fuel economy and what you'll pay per gallon.
- 3
Set the extrasTurn on round trip and set how many people are splitting it.
- 4
Read the resultYou'll see total cost, gallons, per mile, and each share.
Sample trip costs
These one-way examples assume gas at $3.50 a gallon, to show how distance and MPG move the total.
| Distance | MPG | Gallons | Cost |
|---|---|---|---|
| 100 mi | 25 | 4.0 | $14.00 |
| 300 mi | 25 | 12.0 | $42.00 |
| 300 mi | 18 | 16.7 | $58.33 |
| 500 mi | 30 | 16.7 | $58.33 |
| 1,000 mi | 22 | 45.5 | $159.09 |
Frequently asked questions
You enter the trip distance, your vehicle's MPG, and the price of a gallon of gas, and it works out the total fuel cost. Behind the scenes it divides the distance by your MPG to get the gallons you'll burn, then multiplies that by the price. It also shows your cost per mile and, if you turn on round trip, it doubles the distance so you don't have to.
If you don't know it offhand, your car's trip computer usually shows it, or you can work it out: fill the tank, drive, refill, then divide the miles driven by the gallons it took. City driving runs lower and highway runs higher, so an average is fine for planning. Most sedans land near 30 MPG, SUVs nearer 22, and trucks lower, so use one of those if you're just estimating.
Yes. Set the number of people sharing the ride and the calculator divides the total fuel cost evenly, so each person's share shows right away. That's handy for a road trip or a carpool, where you'll want a fair number to settle up. The split uses the round-trip total when round trip is on, so nobody's left short on the way home.
It does. Flip on the round-trip switch and the tool doubles your one-way distance before it figures gallons and cost, so the number you see covers there and back. Leave it off for a one-way drive, like a move or a drop-off. Either way the gallons, total, and per-mile figures all line up with the distance the calculator is actually using.
Use the price you'll actually pay at the pump, since it swings by region and by week. If you're planning ahead, a recent local average works well, and you can nudge it up a little to stay safe. The calculator treats the price as dollars per gallon, so for a quick what-if you can try a higher and a lower price to see the range your trip might cost.
Yes on both counts. There's no sign-up and no limit, and every number is worked out in your browser, so nothing you type is sent anywhere. Bookmark it for the next road trip, commute estimate, or carpool, and you'll have your fuel cost, gallons, and per-mile figure in a second. It's a quick way to budget any drive before you set off.
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