Fuel Cost Calculator
This fuel cost calculator works out the petrol cost of any Australian trip from the distance, your car's fuel use and the price per litre. It suits drivers planning road trips or commutes. The default price is the AIP national unleaded average of 238.4 c/L for the week to 25 October 2026.
How this is calculated
- Fuel used (litres) = distance (km) × fuel use (L/100 km) ÷ 100.
- Fuel cost = litres × price per litre. The price box takes cents per litre, so the calculator divides by 100.
- Return trip = one-way cost × 2. Cost per 100 km = fuel use × price per litre.
The default price is the Australian Institute of Petroleum (AIP) national average retail price for regular unleaded petrol, 238.4 c/L in the week to 25 October 2026. The city buttons load the AIP average for each capital city in the same week. The default fuel use of 8 L/100 km is an example only; enter your own vehicle's figure.
Sources
- Australian Institute of Petroleum, weekly national and capital city retail ULP prices, week to 25 October 2026, read 31 October 2026
- Green Vehicle Guide (Australian Government), vehicle fuel consumption search, read 31 October 2026
Worked example
A 450 km drive in a car that uses 8 L/100 km, at the AIP national average of 238.4 c/L:
- 450 × 8 ÷ 100 = 36 litres.
- 36 × $2.384 = $85.82 one way.
- Return trip: 900 km uses 72 litres, which costs $171.65.
Frequently asked questions
How do you calculate the fuel cost of a trip?
Multiply the distance in kilometres by your fuel use in litres per 100 km and divide by 100 to get litres. Multiply the litres by the price per litre. For example, 450 km at 8 L/100 km uses 36 litres, which costs $85.82 at 238.4 cents a litre.
What is the average petrol price in Australia right now?
The national average retail price of regular unleaded petrol was 238.4 cents a litre in the week to 25 October 2026, according to the Australian Institute of Petroleum. Among the capital cities, Perth was lowest at 230.1 c/L and Hobart was highest at 246.8 c/L.
How do I find my car’s fuel consumption?
The Australian Government Green Vehicle Guide lists the combined fuel consumption, in litres per 100 km, measured in the official laboratory test for light vehicles sold in Australia since 2004. Real-world use differs. To measure your own figure, fill the tank, reset the trip meter, drive, refill, then divide the litres added by the kilometres driven and multiply by 100.
Can I use this calculator for diesel or premium petrol?
Yes. Type the price you pay per litre into the price box. The default is the AIP national average for regular unleaded petrol, so replace it with your diesel or premium price for those fuels.
Does the fuel cost include tolls or other running costs?
No. The result is the cost of fuel only. Tolls, parking, servicing, tyres and depreciation are not included.