For many first-home buyers, the first number they want to know is simple: how much can I borrow? The answer is rarely as simple as multiplying your salary by a set figure. Your income matters, but so do your living expenses, existing debts, credit limits, dependants, deposit and the lending policy used to assess your application.
A borrowing-power calculator is a useful place to begin. It can help you test different loan amounts and repayments before you start inspecting properties. However, it remains an estimate. A lender will examine the details behind the figures and may calculate the result differently from another lender.
This guide explains what goes into a first-home buyer borrowing assessment, why results vary, and how to establish a purchase range that works beyond the day your loan settles.
Your borrowing power is not determined by income alone. It is the amount a lender may be prepared to offer after assessing your income, household spending, liabilities and proposed repayments under its own credit policy.
How do lenders calculate borrowing power?
A lender starts with the income it is prepared to accept. From there, it allows for living expenses, existing financial commitments and the repayments on the proposed home loan. Importantly, those proposed repayments are generally tested at a higher interest rate than the rate you may initially pay.
The lender is trying to determine whether sufficient income remains after these commitments to support the new loan. The assessment also considers the requested loan term, number of applicants, number of dependants and the lender’s internal policies.
There is no single industry-wide borrowing calculator. A result from one bank, broker calculator or comparison website should therefore be treated as a guide rather than a guaranteed approval amount.
“The most useful borrowing figure is not necessarily the highest figure. It is the figure that gives the buyer a realistic property budget and sustainable repayments.”
— Nishant Ramavat, Triple O Finance
You can begin with the Triple O Finance borrowing-power calculator , then compare that estimate with a lender-policy assessment before making an offer.
How lenders assess your income
Base salary is usually the most straightforward part of the assessment, but many Australians do not receive only a fixed salary. Nurses, police officers, firefighters and other essential workers may receive overtime, shift penalties and allowances. Other applicants may receive bonuses, commission, casual income or earnings from a second job.
A lender may want to know how long the income has been received, how regularly it is paid and whether it is likely to continue. Depending on the income type and lender, only part of a variable income amount may be included.
| Income type | What a lender may examine | Evidence commonly requested |
|---|---|---|
| Base salary | Employment status, probation, pay frequency and continuity | Recent payslips, income statement and sometimes salary credits |
| Overtime and allowances | History, consistency, occupation and whether earnings are ongoing | Year-to-date payslips and sometimes prior-year evidence |
| Bonus or commission | Variability, payment history and whether the amount is discretionary | Current and previous income records or employer confirmation |
| Casual or second-job income | Time in the role, consistency of hours and sustainability | Payslips, year-to-date income and employment history |
| Self-employed income | Business history, taxable earnings, liabilities, add-backs and recent performance | Tax returns, Notices of Assessment, financial statements or other acceptable evidence |
A first-home buyer with regular overtime or allowances may receive different borrowing results because lenders do not always treat those earnings in the same way.
Living expenses and dependants
Lenders ask applicants to declare their household expenses. These may include groceries, utilities, transport, insurance, medical costs, education, childcare, subscriptions, entertainment and other recurring spending.
The declared figures may be compared with the lender’s minimum expense measure. If your actual spending is higher, the higher amount may be used. Household composition also matters: a single applicant, a couple and a family with dependants will not generally be assessed on the same expense assumptions.
This is why it is important to use realistic figures. Reducing expenses merely to produce a higher online result does not improve your true position and may create problems when transaction accounts and supporting documents are reviewed.
Review several months of household transactions and separate essential, discretionary and temporary expenses. This produces a more reliable budget and makes unusual transactions easier to explain.
How debts and credit limits reduce borrowing capacity
Car loans, personal loans, novated leases, buy-now-pay-later facilities, existing mortgages and other commitments can reduce the income available for a new home loan. The monthly repayment is important, but it is not always the only figure used.
Credit cards are a common source of confusion. Even where the current balance is nil, a lender may assess the available card limit because the facility can be used again. An unused card with a high limit can therefore affect borrowing capacity.
Closing or reducing a facility may improve an assessment, but it should not be done without checking the overall effect. Using savings to repay a debt might increase serviceability while reducing the funds available for the deposit, purchasing costs and emergency buffer.
Commitments a lender may include
- Credit-card and store-card limits
- Personal loans and car loans
- Novated leases
- Buy-now-pay-later accounts
- Existing residential or investment mortgages
- Tax debts and formal payment arrangements
- Child support and other continuing commitments
Does HECS or HELP debt affect how much you can borrow?
A study or training loan does not automatically prevent you from obtaining a home loan. However, the compulsory repayment associated with your repayment income reduces the cash flow available in the lender’s assessment.
The size of the outstanding HELP balance and its effect on borrowing capacity are not always proportional. A relatively small remaining balance may continue to create a compulsory repayment until it has been cleared and acceptable evidence is available.
Repaying HELP before applying is not automatically the best strategy. The cash used to clear it might otherwise strengthen your deposit, cover purchasing costs or remain available as an emergency buffer. The alternatives should be calculated before a decision is made.
For a more detailed explanation, read Does HECS stop you from getting a home loan?
Your deposit and borrowing capacity are two separate limits
Your deposit determines how much of the purchase price you can contribute. It can affect the loan-to-value ratio, possible lenders mortgage insurance, government assistance options and the amount of cash left after settlement.
Borrowing capacity answers a different question: how much debt does the lender believe your household can support? A buyer may have a substantial deposit but insufficient assessed income for the required loan. Another buyer may have strong income but insufficient funds for the deposit and purchasing costs.
A realistic property price therefore needs to satisfy both tests. It should also allow for stamp duty where applicable, conveyancing, inspections, moving costs and an appropriate post-settlement buffer.
Use the first-home buyer scheme eligibility checker to identify pathways worth exploring, then assess the mortgage repayments separately.
Why lenders assess repayments at a higher interest rate
A lender normally tests the proposed home loan at an interest rate above the rate the borrower may initially pay. For banks regulated by APRA, the current minimum mortgage serviceability buffer is three percentage points above the loan interest rate.
The purpose is to test whether the household may be able to manage repayments if rates or financial circumstances become less favourable. A lender may also apply an assessment floor or other internal assumptions, so the rate used for serviceability can vary.
This helps explain why an online repayment that appears manageable does not automatically translate into the same result under a lender’s calculator. The lender is assessing a stressed repayment rather than only the repayment shown at the advertised rate.
Why two lenders can produce different results
The broad assessment principles are similar, but the details can differ. One lender may accept more overtime income, another may apply a different assessment rate, and another may calculate an existing liability more conservatively.
Common points of difference include:
- How overtime, allowances, bonuses and commission are treated
- The history required for casual or variable income
- The assessment rate and minimum interest-rate floor
- How household expenses and dependants are assessed
- The treatment of credit cards, leases and existing mortgages
- The maximum acceptable loan term for the applicant
- Policies relating to the property and overall borrower profile
This does not mean the lender offering the largest amount is automatically the most suitable option. The interest rate, fees, features, loan structure, conditions and long-term affordability still matter.
Three examples of how the assessment can change
The following examples are illustrative only. They show why the details behind a salary figure can be more important than the salary figure itself.
Example 1: A nurse with shift income and HELP debt
The applicant receives a base salary, regular shift penalties and overtime. The assessment depends on how much variable income the lender accepts, the available income history and the compulsory HELP repayment.
Main checks: year-to-date income, variable-income history, HELP obligation, living expenses and available deposit.
Example 2: A couple with a child, a car loan and credit cards
The combined salary appears strong, but childcare expenses, the car repayment and available credit-card limits reduce serviceability. Reducing a limit may help, while using deposit funds to clear the car loan may create a different issue.
Main checks: dependant expenses, credit limits, remaining car-loan term and the funds required to purchase.
Example 3: A police officer with allowances and overtime
The applicant’s total earnings are meaningfully higher than the base salary. The outcome depends on whether the lender accepts each allowance, what proportion of overtime it uses and the evidence available to demonstrate consistency.
Main checks: acceptable income components, employment history, existing liabilities, loan term and lender policy.
How to prepare before requesting pre-approval
The aim is not to make your finances appear artificially stronger. It is to remove avoidable issues and ensure the assessment uses complete, accurate information.
- Estimate your starting position. Use the borrowing-power calculator and the loan repayment calculator to test a range rather than a single maximum figure.
- Check your credit report. Correct genuine errors and avoid unnecessary credit applications before seeking pre-approval.
- Prepare current income evidence. Include documents supporting overtime, allowances, bonuses, commission or secondary employment where relevant.
- Review your liabilities. Identify unused limits and calculate whether reducing or closing a facility would meaningfully improve the overall position.
- Confirm your available funds. Separate the deposit, purchasing costs and the cash buffer you want to retain after settlement.
- Seek an assessed position. A first-home buyer pre-approval assessment can identify lender conditions before you commit to a property.
Changing employment, applying for new credit or moving deposit funds can affect an application. Discuss material changes before taking action.
Maximum borrowing power versus a comfortable budget
A lender’s maximum figure is an assessment outcome, not a recommendation about how much you should spend. Your household budget should allow for mortgage repayments as well as council rates, strata fees where applicable, home insurance, utilities, maintenance and future changes to income or expenses.
It can be helpful to work with three figures:
- Maximum lender amount: the upper loan amount available under the lender’s assessment.
- Maximum cash-supported purchase price: the price your deposit can support after allowing for purchase costs and a remaining cash buffer.
- Comfortable purchase range: the price that fits your preferred repayments, ownership costs and other financial goals.
For many buyers, the comfortable figure is lower than the maximum. Establishing that distinction before inspecting properties can prevent the search from becoming anchored to an amount that places too much pressure on the household budget.
Start with a calculator, confirm the result against lender policy, and then set a purchase range based on the deposit, total acquisition costs and repayments you are comfortable maintaining.
Continue planning your first-home purchase
These guides cover the next decisions that commonly follow a borrowing-capacity assessment.
Important information: This article provides general information only and does not constitute personal financial, tax or legal advice. Borrowing-power figures vary by lender, product, interest rate, assessment method and individual circumstances. Calculator results are estimates and do not represent pre-approval or formal approval. Loan approval is subject to lender assessment, verification and acceptable security.
