Proven Tips to Calculate Your Borrowing Capacity

Your borrowing capacity is the maximum loan amount a lender will approve based on your income, expenses, and financial commitments.

Most lenders use a servicing calculator that applies a buffer rate around 3% above the actual interest rate to test whether you can afford repayments if rates rise. They also subtract your existing debts, credit card limits, and living expenses from your income to determine how much is left over each month. The result is the amount they're comfortable lending you.

How Lenders Calculate Your Income

Lenders assess your income differently depending on how you're paid. If you're a PAYG employee, they typically use your base salary shown on your payslips and tax return. Overtime, bonuses, and commission are sometimes included, but only if you've received them consistently for at least six months or longer.

If you're self-employed, lenders usually average your taxable income over the past two years. This can reduce your borrowing capacity if you've claimed significant deductions or had a lower-income year recently. Consider someone who runs a small business in Cannon Hill and earned $85,000 one year and $95,000 the next. The lender would use an average of $90,000, not the higher figure, and then assess that against declared expenses and debt commitments.

Rental income from an investment property is generally included, but lenders apply a shading factor of around 80% to account for vacancy periods and maintenance costs. If you're earning $500 per week in rent, the lender might only count $400 toward your borrowing capacity.

The Role of Existing Debts and Credit Limits

Every debt you hold reduces how much you can borrow. Lenders don't just look at what you owe, they look at what you could owe.

If you have a credit card with a $10,000 limit but only owe $1,000, the lender assumes you could max out that card tomorrow. They'll factor in a repayment based on the full limit, usually around 3% of the total each month. That's $300 per month subtracted from your available income, even if you rarely use the card.

Personal loans, car loans, HECS debts, and buy-now-pay-later accounts all work the same way. The monthly repayment on each commitment is deducted before the lender calculates how much you can afford to borrow. Closing unused credit accounts or paying down existing loans before you apply can make a noticeable difference to the loan amount you're approved for.

Living Expenses and the HEM Benchmark

Lenders estimate your living expenses using either the Household Expenditure Measure (HEM) or your actual declared expenses, whichever is higher. The HEM is a standardised benchmark that varies by income level, household size, and location.

If you're a single person earning $80,000 in Cannon Hill, the HEM might estimate your monthly living costs at around $2,000 to $2,200, depending on the lender. If your actual spending is lower, the lender will still use the HEM. If your actual spending is higher, such as $2,800 per month in rent, childcare, and groceries, the lender will use that figure instead.

This calculation can catch people out when they're renting in a suburb close to the CBD. A borrower paying $550 per week in rent near Wynnum Road will have higher assessed expenses than someone living with family, even if their income is identical. The difference might reduce their borrowing capacity by $50,000 or more, depending on the lender's serviceability model.

Interest Rate Buffers and Serviceability Tests

Lenders don't assess your repayments based on the current variable rate. They add a buffer of around 3% to test whether you could still afford the loan if rates increased sharply.

If the actual variable interest rate is 6.5%, the lender might assess your application at 9.5%. This is called the assessment rate. Your loan amount is calculated based on what you could afford at that higher rate, even though you'll be paying the lower rate when the loan settles.

This buffer protects both you and the lender, but it also limits how much you can borrow. A borrower with $8,000 in monthly income and $3,000 in expenses might be able to afford a $700,000 loan at the actual rate, but only qualify for $550,000 once the buffer is applied.

Some lenders apply higher buffers or stricter serviceability tests, while others are slightly more flexible. This is one reason why home loan options vary across different lenders, even when the advertised interest rate looks similar.

How to Improve Your Borrowing Capacity Before You Apply

You can increase how much you're able to borrow by adjusting a few things before you submit a home loan application.

Start by reviewing your credit report. If there are old accounts you no longer use, close them. If you have a credit card with a high limit, either reduce the limit or close the account entirely. Even a $5,000 reduction in credit limits can add $20,000 to $30,000 to your borrowing capacity, depending on your income and other commitments.

Pay down personal loans or car loans where possible. A $400 monthly car payment reduces your borrowing capacity by roughly $80,000 to $100,000 over a 30-year loan term. If you can clear that debt before applying, the difference shows up immediately in the serviceability calculation.

If you're self-employed, speak to your accountant about how your taxable income is structured. Borrowing capacity is based on what you declare, not what you earn. Reducing deductions in the lead-up to a loan application can improve your position, but it's a trade-off that needs to be planned in advance.

For PAYG employees, consistent income is more valuable than variable income. If you've recently changed jobs or started receiving overtime, wait until you have at least three months of payslips showing the new income before applying. Lenders are more confident when the income is stable and documented.

Why Pre-Approval Reflects Borrowing Capacity, Not Property Value

A home loan pre-approval tells you how much a lender is willing to lend based on your financial position. It doesn't confirm the property you're buying is suitable security.

Consider a buyer who receives pre-approval for $600,000 and then makes an offer on a unit in Cannon Hill near the Gateway Motorway. If the lender's valuer assesses the property at $580,000 instead of the $600,000 purchase price, the buyer will need to cover the shortfall or renegotiate. The borrowing capacity was there, but the loan amount is capped by the lower valuation.

Pre-approval also doesn't account for changes in your financial position between approval and settlement. If you take on a new debt, change jobs, or reduce your income, the lender may reassess your capacity before finalising the loan. This is why it's important to avoid applying for new credit or making large purchases between pre-approval and settlement.

Once you know what you can borrow, you can make informed decisions about which properties are within reach and how much deposit you'll need to avoid Lenders Mortgage Insurance if that's a priority.

Call one of our team or book an appointment at a time that works for you. We'll run through your income, commitments, and goals to give you a clear picture of your borrowing capacity and which lenders are most likely to support your application.

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