Borrowing Power in Australia — How Banks Size Home Loans

Serviceability in plain language

Australian lenders assess whether you can “service” the loan after living expenses, other debts, and interest rate buffers. They often apply higher assessment rates than your actual loan rate to simulate future rate rises, and they benchmark living costs using models such as the Household Expenditure Measure (HEM) or your declared expenses—whichever is higher.

That means two households with identical incomes can receive different borrowing limits based on spending patterns, dependants, credit limits, and whether income is base, commission, or overtime.

LVR, LMI, and interest-only

Loan-to-value ratio affects pricing and whether Lenders Mortgage Insurance (LMI) applies. LMI protects the lender but is commonly paid by the borrower when borrowing above typical 80% LVR thresholds (policies vary). Interest-only (IO) periods reduce short-term repayments but do not build principal; regulators cap riskier IO lending, so do not assume IO is available for every LVR.

Our Australia calculator lets you compare repayment paths; always confirm IO availability and LMI quotes with your credit adviser.

Why the bank’s number beats the headline calculator

Banks add buffers, use verified payslips, and apply haircuts to variable income. Public calculators—including ours—use simplified ratios for orientation. Expect the bank’s figure to be the authoritative one.

Illustrative scenario

Consider a Sydney couple with $150,000 combined base income, moderate credit card limits, and one child. Their assessed expenses might be lifted above self-reported spending because of HEM, lowering borrowing power versus a naive income-multiple guess. Modelling both repayment and interest-only (if available) shows cashflow trade-offs even before LMI is layered in.

Use our Australia home loan calculator to rehearse your own income, debts, rate, and term before you speak to an ACL holder.