How long the money lasts, what the road costs, and what is in every town you stop in.
A national park night comes to $31 for 4 of you. Queensland Parks charges per person with a family cap, so tick a stop as a park and it prices itself. Under fives are free, so leave them out of the count. Rates are the published Queensland ones and every state sets its own, so change them when you cross a border.
Nothing planned yet. Add the first leg and the totals fill in underneath.
Most people work out a lap by taking a monthly figure and multiplying it. Two things go wrong. A month is 4.33 weeks, not four, so a year of spending comes out a month short. And nobody tows four hundred kilometres a day seven days a week: you move, then you sit somewhere for a few days, so fuel follows how many driving days there are rather than a flat distance. Both are handled here, which is usually the difference between the plan and what the bank account does.
The other one is sites. A powered site in a tourist town in July is not the same money as a national park in the shoulder season, and the mix is what decides whether you last six months or fourteen. Put a couple of real legs in and the per night figure it gives you back is usually a shock, in a useful way.
Diesel comes off the state fuel price reporting scheme, so the figure on the map is the one on the board rather than a guess. Camps and things to do are a mix of OpenStreetMap and what other travellers have added.
Nothing here is financial advice and your plan never leaves your browser. There is no login, because a tool that wants your email before it answers anything is not a tool.