Budget planner
What's your real monthly surplus?
Enter your household income and monthly expenses. See exactly what surplus is available for loan repayments or savings, and how much borrowing power that surplus supports at Perth rates. It updates as you type.
Borrowing power estimate uses a 3 percentage point serviceability buffer above 6.20%, principal and interest, 30 year term. Indicative only. Actual lender assessment varies by lender, income type, and HEM minimums. Not credit assistance.
Why this matters
What this planner is actually telling you.
Every mortgage decision in Perth starts with the same question, how much surplus do you have per month after everything else is paid? That number, multiplied by a serviceability buffer, is what determines your borrowing power. A $1,000 uplift in monthly surplus translates to roughly $150,000 more in home loan approval at current Perth rates.
Lenders use HEM benchmarks alongside your declared spending, so they may assess higher expenses than you claim. But your real surplus is still the honest floor for what you can service. Bringing it into focus, then hunting for room to lift it, is the fastest way to grow borrowing power without earning more.
Questions
Frequently asked.
What income and expenses do lenders actually count?
Australian lenders count gross salary before tax, some allowances, and consistent bonuses. On the expense side they use HEM (Household Expenditure Measure) minimum benchmarks alongside your declared spending, and typically use whichever is higher. Rent, existing loan repayments, and credit card limits (not just balances) all count as debt commitments. Real spending on eating out, subscriptions, and travel gets factored in during pre-approval.
How does my monthly surplus translate to borrowing power?
Lenders divide your net surplus by an assessment rate that is typically 3 percentage points above the actual quoted rate (currently about 9.20%). At 6.20% actual, a $1,240 monthly surplus supports around $185,000 in additional borrowing over 30 years. This is a rough guide, the exact multiplier depends on the lender's buffer, term, and their treatment of your specific income sources.
Should I include my partner or run this solo?
Enter combined household income and expenses if you plan to apply jointly. Most Perth couples apply jointly to maximise borrowing power, though there are cases where applying solo is better (one partner has bad credit or high existing debt). A broker can model both scenarios and tell you which application shape produces the higher approval.
Does this affect my credit score?
No. The calculator runs entirely in your browser. Nothing is submitted, recorded, or shared with a lender. Your credit file is untouched.
How accurate is this planner?
It is a starting point, not a lender submission. Actual borrowing power depends on lender-specific assessment rules, HEM minimums, your credit file, and your specific income structure. A Central Lending Solutions broker will run your real numbers across 30+ lenders and give you an accurate figure before you commit to a property.
Want this applied to your real situation?
Talk to Harj.
No fee for most clients. A real conversation about your numbers and your options across 30+ lenders. Most clients hear back the same day.