Where to start
If you don't know how much you can borrow yet, start with the deposit and loan-to-value calculator. The loan size it gives you sets every other number, so the repayment calculator is most useful once you have it. Then check whether the repayment fits the budget you'd set, weekly, fortnightly or monthly.
Once an offer is accepted, the settlement dates calculator turns your settlement date into a schedule of the moving-day jobs. For the bigger picture, the buying guide walks through the stages from budget to settlement, in order.