Planning a road trip

Australian distances make fuel the dominant cost of a long drive, and the two numbers that decide it are consumption and the pump price. Both are easy to get wrong: the windscreen label understates real-world consumption, and fuel prices vary a great deal once you leave a capital city.

This collection costs a trip from the numbers you can actually verify, then sanity-checks the driving time.

Working through it

1. Step 1

   Measure your real consumption

   Work out your own L/100 km from a brim-to-brim fill rather than trusting the official figure. On a loaded car at highway speed the real number is usually worse than the label.

   Open the fuel economy calculator

2. Step 2

   Cost the fuel for the distance

   Combine the distance, your consumption and a price per litre. Try a price a good deal higher than city prices for the remote legs of a trip.

   Open the fuel calculator

3. Step 3

   Estimate the driving time

   Distance divided by an average speed. Use an average well below the speed limit to allow for towns, roadworks and fuel stops, then add rest breaks separately.

   Open the travel time calculator

4. Step 4

   Convert distances

   For maps, guidebooks or overseas sources quoting miles, convert to kilometres before doing anything else.

   Open the length calculator

What these tools do not cover

• Fuel prices move weekly and vary widely by region, so a trip cost is only as good as the price you assume.
• Travel time excludes rest breaks, traffic and road closures. Driver fatigue guidance is a safety matter, not an arithmetic one.
• Tolls, accommodation, food and vehicle wear are not included in a fuel cost.

Each calculator lists its own assumptions and sources in full. Results are estimates — see the disclaimer for what that means before you rely on a figure.