Layer multiple life events onto your Australian mortgage to model the combined impact on your 60-month cashflow - including a rate rise, a parental leave period, a job loss, or a medical expense - and see which month the buffer would be exhausted if all events occurred. A required-buffer solver shows the minimum cash reserve needed to stay afloat across your chosen scenario combination.

Why stack events instead of testing one at a time?

Most missed mortgage payments in Australia trace back to a combination - a parental leave overlapping a rate rise, a medical event landing during a job search. Testing one factor at a time understates the real-world buffer needed. Stacking layered events shows the cumulative drag on cashflow.

What does the required buffer actually mean?

It is the smallest pile of starting cash that, given the events you have turned on, keeps the cumulative cashflow above zero in every month of the 5-year horizon. A 10% safety margin is added on top of the worst-month shortfall to absorb minor variability.

How does parental leave income drop work?

The chosen partner's net income falls to the paid leave percentage for the paid leave months, then to zero across any unpaid months, then returns to the chosen return percentage. Childcare costs only kick in from the month they return to work, for the duration you set.

Does this include Government Paid Parental Leave or employer top-ups?

Not by default. The paid leave percentage and length are user-controlled, so you can model Government PPL (20 weeks at the national minimum wage in 2026) plus any employer top-up by adjusting those numbers. Services Australia and your employer are the right places to confirm exact entitlements.

Why is the result different to ASIC's 3-month emergency fund rule?

ASIC MoneySmart recommends 3-6 months of expenses as a general buffer. This tool computes a buffer specific to the scenario you build. Once you start stacking events (rate rise plus parental leave plus childcare costs, for example), the figure can easily exceed the rule-of-thumb. See Am I Ready for a broader readiness check.

Can the simulator tell me which lender to pick or whether to refinance?

No. This is a scenario simulator, not a product recommendation. If you want to compare specific loan structures or refinance pathways, the Mortgage Comparison and Refinance Break-Even tools cover that ground. A licensed broker or your lender can give product-specific advice.