A useful trip budget can survive a changed hotel booking or an extra person. Write down the units first: rooms per night, food per person per day, and airport travel for the whole group.
A worked example, with every assumption visible
The figures below are deliberately editable sample inputs. They are not researched Sydney hotel rates, restaurant prices or a transport quote. The example is two adults sharing one room for four nights, with five days of food and local travel.
| Cost | Calculation | Group total |
|---|---|---|
| Accommodation | A$180 × 1 room × 4 nights | A$720 |
| Food | A$45 × 2 adults × 5 days | A$450 |
| Local transport allowance | A$12 × 2 adults × 5 days | A$120 |
| Activities | A$40 × 2 adults, for the trip | A$80 |
| Airport transfers | A$80 for the whole group | A$80 |
| Subtotal | Before contingency | A$1,450 |
| Contingency | 10% of the subtotal | A$145 |
| Total | Whole trip, whole group | A$1,595 |
Change the expensive unit first
In this example, an extra A$40 per room per night adds A$160 to the accommodation line. With the same 10% contingency it adds A$176 to the total. An extra A$10 of food per person per day adds A$100 before contingency, or A$110 after it. This comparison tells you which change deserves attention before you start removing small purchases.
Adding a third adult does not automatically require a second room. Check the actual booking's occupancy and extra-person charges, then update room count or nightly cost. Our calculator makes you choose those quantities separately instead of pretending every group scales in the same way.
Four nights can require five days of spending
Count arrival and departure food and transport explicitly. A late departure might need a full day's allowance after the fourth hotel night. Conversely, a very late arrival may need little beyond the transfer. Use the trip-days field for your spending days and keep hotel nights independent.
Already paid is not the same as free
If the A$720 accommodation is already paid, the estimated total remains A$1,595. The amount still to fund becomes A$875. Removing the accommodation line entirely would hide the cost of the trip and make comparisons with another itinerary misleading.
Open the editable budget, replace each sample with your own amount, and keep airport transfers in one place. If a transfer has already been included in a package or another line, enter zero for that duplicate cost. Keep the contingency for uncertainty rather than adding the same buffer twice.
Sources and what we checked
Official information checked 25 October 2026. Our cost examples, time allowances and route choices are our planning analysis. They are not live quotes or a record of an on-site inspection.