How banks calculate first home buyer borrowing power
Why your own budget and a lender’s assessment can produce very different answers—and what you can do about it.
Borrowing power is a lender assessment, not a personal budget
A lender estimates whether repayments remain manageable under its credit policy. It starts with verified income, subtracts assessed living expenses and existing commitments, and tests the proposed loan at a higher assessment rate. That is why the result can be lower than the repayment you feel comfortable making today.
The details that change the result
Income type, dependants, credit-card limits, other debts, loan term and the property purpose can all affect the calculation. Overtime, bonuses, commissions, casual income and rental income may be treated differently between lenders.
- Close or reduce unused credit limits where appropriate.
- Use realistic living expenses rather than an optimistic estimate.
- Keep evidence for variable or self-employed income organised.
- Allow for purchase costs and a cash buffer, not only the deposit.
Why two banks can give different answers
Lenders use different expense benchmarks, income rules, buffers and debt calculations. A strong result with one lender does not automatically make that lender the best overall choice: rate, fees, features, approval policy and long-term flexibility still matter.
A practical way to prepare
Review your credit limits and recurring commitments, prepare current income evidence and test several purchase prices before making an offer. An indicative calculator is useful for planning, but a broker assessment can compare the way relevant lenders are likely to view the same application.
Important information
This article provides general information only and does not take your objectives, financial situation or needs into account. Lending policies and government programs can change. Seek personalised credit assistance before acting.