Practical guide
How to Calculate Fuel Cost for a Trip
Trip fuel cost is total distance divided by 100, multiplied by litres used per 100 km and the fuel price per litre. The quality of the estimate depends on realistic inputs.
Fact checked and updated 13 September 2026
Use total distance
Include the return journey, local driving and planned detours. A route estimate may differ from the odometer because of roadworks, stops and the exact start and destination points.
Use real consumption
The manufacturer figure can be lower than real driving consumption. Use a recent average from the vehicle display or calculate litres filled divided by kilometres travelled, multiplied by 100.
Allow for changing conditions
Speed, traffic, gradients, air conditioning, tyre pressure, load and towing can increase consumption. Fuel prices also differ by fuel type and location, so update the price shortly before travelling.
Use the related calculators
Apply the explanation above with your own figures. Open a calculator below, check every input and review the result assumptions before making a decision.
Official source checked
This guide was checked against Department of Mineral and Petroleum Resources fuel prices. Rules, rates and institutional requirements can change, so confirm time-sensitive information at the official source.