Fuel Cost Calculator
Estimate fuel used, fuel cost, tolls and each traveler’s share for one trip or repeated journeys.
Trip estimate
Fuel cost formulas
The calculator converts distance, fuel economy and fuel price to kilometers, liters and price per liter before calculating. This avoids mixing US gallons, imperial gallons and liters.
- US MPG: liters used = miles ÷ MPG × 3.785411784.
- Imperial MPG: liters used = miles ÷ MPG × 4.54609.
- L/100 km: liters used = kilometers × L/100 km ÷ 100.
- km/L: liters used = kilometers ÷ km/L.
- Fuel cost: liters used × price per liter.
- Total trip cost: fuel cost + tolls and other entered costs.
Checked examples
| Inputs | Fuel | Fuel cost |
|---|---|---|
| 300 miles one way, 30 US MPG, $3.50/US gal | 10 US gal (37.854 L) | $35.00 |
| 500 km, 8 L/100 km, €1.70/L | 40 L | €68.00 |
| 400 km, 16 km/L, $1.50/L | 25 L | $37.50 |
How to estimate a trip accurately
- Use the route distance for one direction and select round trip only when you will return by the same approximate distance.
- Use your vehicle’s observed fuel economy when available. Official ratings may differ from real driving.
- Enter the local price in the unit sold at the pump. The currency symbol is intentionally not fixed.
- Add tolls, parking or other route costs only if you want them included in the trip total.
Traffic, speed, weather, elevation, towing, tire pressure, idling and vehicle load can change actual consumption. This calculator is an estimate, not a guarantee of fuel use or price.
Frequently asked questions
Does MPG mean a US or imperial gallon?
It can mean either. Choose the correct MPG option because an imperial gallon is larger than a US gallon. Mixing them changes the estimate by about 20 percent.
Should I enter the round-trip distance?
Enter the one-way distance and select Round trip. If your distance already includes both directions, select One way so it is not doubled.
Can I split the cost among passengers?
Yes. The cost per traveler divides the complete total, including any entered tolls or other trip costs, by the number of travelers.
Are tolls multiplied for repeated journeys?
No. The extras field is treated as the total extra cost for all journeys shown. Enter the combined toll and parking amount you expect to pay.
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