Estimate your road trip fuel cost by distance, fuel efficiency, and gas price.
City: ~20–28 MPG · Highway: ~30–40 MPG · Hybrid: 45–60 MPG
Fuel is one of the largest variable expenses for vehicle owners. Whether you're budgeting for a road trip, comparing the true cost of two vehicles, calculating a daily commute expense, or figuring out how much to charge for mileage reimbursement, knowing your exact fuel cost gives you actionable financial data.
Fuel cost calculations are also useful for comparing driving vs. flying, deciding whether to carpool, evaluating EV savings over a gas vehicle, or planning a budget for a cross-country move. The calculator supports both imperial (MPG, miles, gallons) and metric (L/100km, kilometres, litres) units.
Imperial
Gallons used = Distance (mi) / MPG
Total cost = Gallons × Price/gallon
Metric
Litres used = (Distance (km) / 100) × L/100km
Total cost = Litres × Price/litre
Example — 600-mile road trip at 32 MPG, gas at $3.60/gallon:
Gallons used = 600 / 32 = 18.75 gallons
Total cost = 18.75 × $3.60 = $67.50
Cost per mile = $3.60 / 32 = $0.1125 per mile
| Vehicle Type | City MPG | Highway MPG | L/100km (highway) |
|---|---|---|---|
| Large SUV / Truck | 14–18 | 18–22 | 10.7–13.1 |
| Mid-size SUV | 18–24 | 24–30 | 7.8–9.8 |
| Compact Car | 26–34 | 34–42 | 5.6–6.9 |
| Mid-size Sedan | 22–28 | 30–38 | 6.2–7.8 |
| Hybrid | 42–52 | 38–50 | 4.7–6.2 |
| Plug-in Hybrid (EV range) | 80–120 MPGe | 70–100 MPGe | 2.4–3.4 |
Maintain optimal speed
Drive 55–65 mph on highways. Aerodynamic drag rises sharply above 60 mph, reducing efficiency by 10–15% at 75 mph.
Smooth acceleration and braking
Aggressive driving wastes 15–30% more fuel. Anticipate stops and accelerate gradually to cruise speed.
Check tire pressure
Under-inflated tires increase rolling resistance. Proper inflation can improve MPG by 0.5–3%.
Reduce idling
Idling gets 0 MPG. If stopped more than 60 seconds, it's more efficient to turn off the engine.
Plan smarter routes
Use navigation to avoid traffic. Stop-and-go city driving uses 2–3× more fuel than steady highway driving.
Compare fuel prices
Apps like GasBuddy show nearby prices. On a 400-mile trip using 15 gallons, a $0.20/gallon saving is $3 — worth a small detour.
Fuel cost = (Distance / MPG) × Price per gallon. For a 400-mile trip at 30 MPG with $3.50/gallon: (400/30) × $3.50 = $46.67.
L/100km = 235.214 / MPG. So 30 MPG = 7.84 L/100km. Conversely: MPG = 235.214 / (L/100km).
Mid-size sedan: 20–28 city, 28–40 highway. SUV/truck: 15–25 city, 20–30 highway. Hybrid: 45–60 combined. EV equivalent: 80–130 MPGe.
At 30 MPG and $3.50/gallon: (100/30) × $3.50 = $11.67. At 25 MPG and $4.00/gallon: $16.00. Cost per mile = fuel price / MPG.
Drive at 55–65 mph for best efficiency. Avoid hard braking and aggressive acceleration. Maintain proper tire pressure. Use GasBuddy or similar apps to find cheaper fuel.
Fuel use increases sharply above 60 mph. Driving at 75 mph vs 60 mph reduces efficiency by 10–15%. Best efficiency is typically 55–65 mph.
For families of 3+, driving often beats flying even on longer trips. Factor in parking, baggage fees, time, and tolls. Use the calculator to find the per-person driving cost to compare.
Fuel cost = (km / 100) × L/100km × price per litre. Example: 300 km at 8 L/100km at £1.50/L: 3 × 8 × £1.50 = £36.
Calculation method: Imperial: Fuel used = Distance / MPG; Cost = Fuel × Price/gallon. Metric: Fuel used = (Distance/100) × L/100km; Cost = Fuel × Price/litre. Disclaimer: Estimates only. Actual fuel consumption varies by vehicle condition, load, terrain, traffic, and driving style. Last updated: September 2026. Maintained by The Free Calculator Site.
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