Fuel cost calculator
Enter the distance, what your car drinks and what fuel costs where you're driving. Works in litres and kilometres or gallons and miles, doubles the distance for a return trip, and splits the total between however many of you are going.
Estimates only. Fuel prices change daily and consumption depends on load, terrain and how you drive — treat the result as a planning figure, not a quote.
Turn this into a real trip
We'll carry these numbers into the planner: your distance, vehicle and consumption become the first draft of a day-by-day itinerary.
Build the itinerary →How the numbers work
Fuel cost has only three inputs, and people get two of them wrong. The distance is usually underestimated because a road trip is not a straight line — detours, wrong turns and the drive to dinner add up to more than you'd guess over a week. And the consumption figure most people use is the manufacturer's, measured in conditions nobody drives in.
A useful habit: take your real-world consumption, add 10% for a loaded car, and add another 10% if the route is mountainous. That gets you close enough to budget with, and it is a better number than any estimate a rental brochure will give you.
Typical consumption by vehicle
| Vehicle | L/100 km | MPG (US) |
|---|---|---|
| Compact petrol car | 6–8 | 30–39 |
| Mid-size petrol car | 7–9 | 26–34 |
| Large SUV | 9–12 | 20–26 |
| Campervan | 9–12 | 20–26 |
| Large motorhome | 20–25 | 9–12 |
Ranges, not promises — use your own measured figure whenever you have one.
Questions, answered
- How do you calculate fuel cost for a trip?
- Multiply the distance by your consumption to get the volume of fuel, then multiply that by the price. In metric: litres = km × (L/100 km) ÷ 100, then cost = litres × price per litre. In imperial: gallons = miles ÷ MPG, then cost = gallons × price per gallon. The calculator above does both and handles the round-trip doubling.
- What fuel consumption figure should I use?
- Your own measured one if you have it — fill up, drive, fill up again, and divide. Manufacturer figures are optimistic, and a loaded car with a roof box in the mountains can be 20–30% worse. If you're renting, assume something typical for the class: roughly 6–8 L/100 km (30–40 MPG) for a compact, 9–12 (20–26 MPG) for a large SUV, and 20–25 (10–12 MPG) for a motorhome.
- Does the calculator include tolls?
- Not here — this page is fuel only, which keeps it honest for the many trips with no tolls at all. The road trip cost calculator adds tolls, accommodation and food to give a whole-trip figure.
- How accurate is a fuel estimate?
- Within about 10% if your consumption figure is real and the price is current. The two things that move it most are terrain and speed: sustained motorway driving above 120 km/h and long climbs both hurt consumption noticeably.
- Is the fuel cost per person or per car?
- The total is per car. Enter the number of people sharing and the calculator also shows the per-person split — which is the number you actually want when you're dividing the cost at the end of the trip.