Fuel Cost Calculator
Enter the trip distance, your vehicle’s fuel economy and the price of fuel to see how much fuel you will need and what it will cost. Switch to metric units, make it a round trip or split the cost between passengers.
Last updated October 23, 2026
Result
Fuel cost = $35.00
| Measure | Value |
|---|---|
| Distance driven | 300 miles |
| Fuel needed | 10 gallons |
| Fuel cost per distance | $0.117 per mile |
Estimate only. Real mileage changes with speed, load, weather and traffic.
Show the work
Formula: fuel = distance / MPG; cost = fuel x price per gallon
- Entered: 300 miles, 30 MPG, $3.5 per gallon, one way, 1 person.
- Distance: 300 miles.
- Fuel needed: 300 miles / 30 MPG = 10 gallons.
- Cost: 10 gallons x $3.500 = $35.00.
Result: Fuel cost = $35.00
How trip fuel cost is calculated
fuel needed = distance ÷ MPG
cost = fuel needed × price per gallon
Divide the distance by the fuel economy to get the fuel used, then multiply by the price of fuel. A 300-mile trip at 30 MPG needs 10 gallons, and at $3.50 a gallon that costs $35.00. A round trip doubles the distance.
In metric units, fuel economy is liters per 100 km, so liters = distance ÷ 100 × L/100 km. The calculator converts to US units internally (1 US gallon = 3.785 liters, 1 mile = 1.609 km), so the result is the same either way. Use the real-world figure from your own trips if you have one: city driving, towing, a loaded car and high speeds all lower fuel economy.
See how we calculate for the formulas, sources and review schedule behind every calculator.
Also useful alongside this calculator: Average Calculator, Mileage Calculator and EV Charging Cost Calculator.
How to use the Fuel Cost Calculator
- Choose US or metric units.
- Enter the distance, your fuel economy and the fuel price.
- Pick one way or round trip, and enter how many people share the cost.
- Read the fuel needed and total cost, then use Copy, Print or Share.
Worked example
A 300-mile trip at 30 MPG uses 300 ÷ 30 = 10 gallons. At $3.50 per gallon that is 10 × $3.50 = $35.00, or about $0.117 per mile. The table shows other distances at $3.50 a gallon.
| Distance | 25 MPG | 30 MPG | 40 MPG |
|---|---|---|---|
| 100 miles | $14.00 | $11.67 | $8.75 |
| 250 miles | $35.00 | $29.17 | $21.88 |
| 500 miles | $70.00 | $58.33 | $43.75 |
| 1,000 miles | $140.00 | $116.67 | $87.50 |
Frequently asked questions
How do I calculate fuel cost for a trip?
Divide the trip distance by your miles per gallon to get gallons, then multiply by the price per gallon.
Can I use kilometers and liters?
Yes. Choose Metric, then enter kilometers, liters per 100 km and the price per liter.
Why is my real fuel cost different?
Speed, traffic, hills, weather, load and tire pressure change fuel economy. Use an MPG you measured on similar trips for the best estimate.
How do I split the cost between passengers?
Enter the number of people sharing the cost to see the cost per person.
Are my numbers stored or sent anywhere?
No. The calculation runs in your browser and nothing you enter is saved or uploaded.