Fuel Cost Trip Calculator
Estimate road trip fuel cost from distance, fuel efficiency, and gas price.
Supports MPG, km/L, and L/100km with total cost and per-mile fuel breakdown.
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 — US road trip: Drive from Los Angeles to Las Vegas: 270 miles | 2023 SUV averaging 28 MPG | Gas: $3.85/gal | 3 passengers
- Gallons: 270 / 28 = 9.64 gallons
- Total fuel cost: 9.64 × $3.85 = $37.12
- Per person: $37.12 / 3 = $12.37 each
Factors that affect real-world MPG vs. EPA 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 outside major cities — highway exit gas is often 10–20¢/gal higher
- Drive at 65 mph instead of 75 mph — can improve fuel economy by 10–15%
- Check tire pressure before departure — under-inflated tires waste fuel