How Much Can I Borrow?

This is your ceiling, not your marching order.

Now test whether the repayment actually fits your budget — before you fall in love with a number that belongs in a lender brochure, not your life.

How this Borrowing Power Calculator works

A borrowing power calculator estimates how much you may be able to borrow by weighing income against debt, living expenses and household commitments, then applying loan assumptions and serviceability buffers behind the scenes. In plain English, it is trying to answer "how much mortgage can your current finances carry before things start looking unsafe on paper?"

The Rebel mistake is to treat the output like a trophy. The Sage move is to treat it like a draft boundary. Borrowing power is useful because it gives you a realistic search range — but it becomes dangerous when borrowers turn the top-end result into a target instead of a warning label.

Different calculators and lenders use different assessment rates, income shading and expense benchmarks. Some are generous with overtime and bonuses, others barely count them. Some are strict on credit card limits and living expenses, others less so. That is why the number on this page is best used as a planning range, then tested immediately in a home loan repayment calculator and followed by upfront-cost tools like stamp duty, LMI and buying-cost calculators.

To keep things transparent, this calculator makes a few working assumptions:

• It assumes a principal-and-interest loan over a typical term such as 30 years unless you change it.
• It applies a 3% test-rate buffer (when toggled on) to mimic the way lenders use APRA-style assessment buffers.
• It assumes your stated living expenses are accurate and at least broadly in line with household size.
• It treats credit card limits as potential debt at roughly 3.8% of the limit per month — not just current balances.
• It treats variable income such as overtime and commission more cautiously than base salary.

What affects your borrowing power most

• Income. Higher and more stable income usually supports a higher borrowing limit, especially if it is base salary rather than volatile bonuses.
• Existing debts. Personal loans, car loans, buy now pay later and other commitments consume part of your budget before the mortgage even shows up.
• Credit card limits. Many lenders assess the limit as if it could be fully used, not just whatever balance is on there today.
• Living expenses. Under-declaring day-to-day costs might inflate the calculator result, but it does not make the future bills disappear.
• Dependants. Kids and other dependants increase typical household spending and can reduce borrowing power.
• Loan term and structure. Longer terms and interest-only periods can improve short-term affordability on paper but may not be wise in real life.
• Assessment buffers. Serviceability tests based on higher assessment rates produce lower borrowing numbers than tools that just use today's sharp marketing rate.

If changing a small number makes a huge difference to your borrowing power, that is a clue that your structure is sensitive and deserves more scrutiny, not less.

How to interpret your results

If the result is lower than you hoped, that does not mean the calculator is broken. It usually means your income, debts, expenses or household setup are drawing a more honest line than your optimism was. That is useful information.

If the result is higher than expected, resist the urge to celebrate too quickly. A lender may tolerate a level of pain you do not actually want to live with. The number that matters most is not the maximum available — it is the level where repayments still leave room for bills, food, insurance, maintenance, kids, transport and the occasional reminder that houses enjoy inventing fresh expenses.

Read the result in three layers:

• Maximum range. What a calculator says may be possible on paper.
• Comfortable range. What still feels manageable under a tougher interest-rate or expense scenario.
• Action range. What you should actually shop within once your deposit and upfront costs are included.

How to find repayments that fit your budget

Once you have your borrowing range, move immediately to the Home Loan Repayment Calculator. Do not stop at "we can borrow this much." Ask what that amount does to your monthly life.

• Start with borrowing power to get a realistic range.
• Take the lower, middle and upper end of that range into the repayment calculator.
• Run at least one tougher scenario with a higher rate, not just the flattering one.
• Compare the result against your actual budget, not a cleaned-up fantasy version of it.
• Then check deposit, LMI, stamp duty and buying costs so you do not confuse "loan approved" with "purchase affordable."

The Rebel instinct says stretch because the bank said maybe. The Sage instinct says keep a buffer because life has no interest in your spreadsheet behaving itself. LoanGorilla sides with the version of you that still wants to sleep at night after settlement.

Calculator assumptions

This calculator produces estimates using a simplified serviceability model: net household income (after a basic PAYG tax estimate) less living expenses, declared debt repayments, a benchmark dependant cost and a credit-card-limit commitment of around 3.8% per month. The remaining surplus is then converted to a maximum loan using the standard annuity formula at your chosen rate and term, with an optional 3% APRA-style assessment buffer. The numbers are mathematically precise for the inputs you enter — but real lenders apply their own income shading, expense floors (HEM benchmarks), credit-card treatment and policy overlays. Your actual borrowing capacity may land materially higher or lower. This calculator does not constitute financial or credit advice. Reviewed by the LoanGorilla editorial team — last updated May 2026.