Fuel Cost Trip Calculator
Estimate road trip fuel cost from distance, fuel efficiency, and gas price.
Supports MPG and L/100km, with per-mile, per-km, and split-per-person totals.
Road trip fuel cost depends on trip distance, your vehicle’s fuel efficiency, and the local gas price at the time of travel. This calculator breaks down total fuel expense and per-person cost for groups.
Core formula:
Gallons Needed = Trip Distance (miles) / MPG
Fuel Cost = Gallons Needed × Price per Gallon
Cost per Person = Fuel Cost / Number of Passengers
For metric users (liters per 100 km):
Liters Needed = (Distance in km × L/100km) / 100
Fuel Cost = Liters Needed × Price per Liter
Worked example, a US road trip: Drive from Los Angeles to Las Vegas: 270 miles | SUV averaging 28 MPG | Gas: $3.85/gal | 3 passengers
- Gallons: 270 / 28 = 9.64 gallons
- Total fuel cost: 9.64 × $3.85 = $37.13
- Per person: $37.13 / 3 = $12.38 each
That is one way. Double it for the return leg unless you are filling up in Nevada, where gas usually runs cheaper than in California.
Factors that affect real-world MPG vs. the EPA (Environmental Protection Agency) estimate:
| Factor | MPG Impact |
|---|---|
| Highway driving (65–75 mph) | Close to EPA estimate |
| City stop-and-go | 15–30% worse |
| Speed above 75 mph | −10 to −20% |
| Air conditioning | −5 to −15% |
| Roof rack / cargo | −5 to −10% |
| Cold weather (below 20°F) | −15 to −25% |
| Proper tire inflation | ±3% |
Long-trip savings tips:
- Use GasBuddy or Google Maps to find cheap gas along your route
- Fill up before you reach a major city or a remote stretch, because highway-exit and interstate-services gas often runs 10–20¢/gal higher
- Drive at 65 mph instead of 75 mph, worth 10–15% on fuel economy
- Check tire pressure before departure, since under-inflated tires waste fuel and wear the shoulders
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.
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