Road trip fuel cost guide (2026)

Work out and estimate fuel costs for road trips in Australia: distance, litres per 100km, pump price, return trips, towing and where to fill up along the way.

By the FuelRadar teamUpdated 23 September 20261 min read

The road trip fuel cost formula

Use this formula: distance in kilometres divided by 100, multiplied by your car's fuel use in L/100km, multiplied by the fuel price in dollars per litre. A 500km drive in a car using 8.0L/100km at $1.85/L costs 500 / 100 x 8.0 x 1.85, or $74.

What numbers you need

Figure	Where to get it	What changes it
Distance	Map route distance	Detours, return trips and route choice
Fuel use	Trip computer or manufacturer figure	Towing, traffic, speed, tyres and load
Price	Current station price for your fuel grade	Price cycle, suburb, brand and update time

Worked examples

Using an illustrative 8.0L/100km and $1.85/L, an 80km one-way drive costs about $11.84, a 160km return trip costs about $23.68, and a 920km interstate drive costs about $136.16 one way. Replace both assumptions with your vehicle's recent fuel use and the grade you will buy.

Adjust for towing and real-world driving

Towing, roof loads, speed, low tyre pressure and heavy traffic can lift fuel use. A combined-cycle manufacturer figure may not represent towing or a loaded highway trip. Use the trip computer from a similar drive where available and allow a sensible budget margin.

Plan fuel stops

Check the station's opening hours, fuel-grade availability, report time and distance from the route. Do not plan to arrive with an empty tank, particularly on a remote drive or where service stations are far apart. Keep one alternative stop in case the planned station is closed or the required fuel is unavailable.

Use the calculator, then check the map

The calculator gives the budget. The map helps with the station choice. Include the return trip and planned side trips, then compare stations along the route for the exact fuel grade your vehicle uses.

Trip cost calculator Check route prices

Common questions

How do I calculate and estimate fuel cost for a trip?

Divide distance by 100, multiply by your L/100km figure, then multiply by the fuel price in dollars per litre. Double it for a return trip. Use the FuelRadar trip cost calculator to estimate fuel costs with current petrol and diesel prices.

Should I use average fuel prices?

Use the current price for the grade you will buy. Local prices can vary enough to change a trip budget, especially during a price cycle.

How much extra fuel does towing use?

It depends on load, speed and vehicle, but towing can lift consumption materially. Use a recent towing trip-computer figure or add a buffer before budgeting.