Travel planning
Fuel cost calculator: estimate your road-trip budget before you leave
Use distance, mileage, and fuel price to estimate the fuel part of a road-trip budget, then leave room for real-world driving conditions.
Updated July 30, 2026 · 4 min read
Calculate the total route distance first
Start with the kilometres you expect to drive, not just the straight-line distance between two places. A navigation route is usually a more useful starting point because it follows the roads you will actually use.
For a return journey on the same route, double the one-way distance. If the return is different, add both route estimates instead of assuming they are identical.
Turn kilometres into litres and cost
Divide the total distance by your vehicle's expected mileage in kilometres per litre. That gives an estimated number of litres. Multiply the litres by the fuel price to estimate the fuel cost.
For example, a 320 km return drive at 16 km per litre needs about 20 litres. Your final cost depends on the local price you enter and the mileage your vehicle actually achieves.
Plan for variation on the road
Traffic, steep roads, weather, passenger load, and air conditioning can increase fuel use. It is sensible to keep a buffer rather than treating the calculation as an exact promise.
Fuel is also not the whole travel budget. Add tolls, parking, food, and accommodation separately before you compare travel options.