Borrowing Power Calculator Australia

A borrowing power calculator gives Australian home buyers a realistic sense of how much they could borrow before they start house-hunting. Rather than guessing, you enter your income, expenses and existing commitments, and the tool estimates the maximum loan you could service, tested the way lenders test it, at a buffered rate.

What the calculator does

Borrowing power is not about how much a lender is willing to hand over in the abstract; it is about how much you can comfortably repay. This calculator works out the monthly surplus left after your living expenses and existing loan repayments, then translates that surplus into the largest loan it could support over a typical term.

It does this at an assessment rate rather than the advertised rate. Lenders add a serviceability buffer to make sure you could still cope if interest rates rose. By building that buffer in, the estimate reflects how a lender would actually view your application, not an optimistic best case.

How it works

The calculation flows from a few inputs:

• Income: your regular, stable earnings.
• Living expenses: your ongoing household spending.
• Existing commitments: current loan repayments, and credit card limits, which reduce capacity.
• Assessment rate: your rate plus a serviceability buffer.

The surplus (income minus expenses and existing repayments) is the amount available for a new repayment. The calculator discounts that surplus over the loan term at the assessed rate to arrive at the maximum loan. Like lenders, it uses the greater of your living expenses and a household benchmark for your household size, counts 3.8% of your total credit card limits as a monthly repayment, and assesses the loan at the greater of your rate plus 3% and a 5.75% floor. Each lender applies its own policy on top, so treat the result as an estimate.

How to use it

1. Enter your income.
2. Enter your regular living expenses.
3. Add existing loan repayments and credit card limits.
4. Read the estimated maximum loan.

Then explore. Reduce a credit card limit and watch capacity rise. Trim discretionary expenses and see the effect. These experiments show you the most effective levers before you speak to a lender.

How to read the result

The headline is your estimated maximum loan. Treat it as an upper guide, not a target. Borrowing the maximum you can service leaves little room for rate rises or life changes, so many buyers deliberately aim below it.

Pay attention to how sensitive the number is to your inputs. If a small change in expenses or debts moves it a lot, that tells you how tight your position is and where to focus. Reducing commitments before applying can meaningfully lift your capacity.

The calculator uses the assessment logic and buffer it is configured with, kept up to date. A real lender will apply detailed expense benchmarks, verify your income and follow its own credit policy, so your formal assessment may differ. Use this to plan and prioritise, then confirm with a lender or broker.

Practical tips

• Reduce credit card limits. Lenders count the full limit, not the balance, so lowering or closing unused cards can lift your borrowing power.
• Clear small debts. Personal loans and buy-now-pay-later commitments reduce your surplus and weigh on serviceability.
• Show stable income. Consistent, verifiable income supports a stronger assessment than irregular earnings.
• Leave a buffer. Borrowing below your maximum protects you against rate rises and unexpected costs.

Why the assessment rate matters

The feature that most distinguishes a genuine borrowing power estimate from an optimistic one is the assessment rate. Lenders do not test whether you can afford repayments at today's advertised rate; they test whether you could still afford them if rates rose, by adding a serviceability buffer. This protects both you and the lender against the risk that rates increase after you borrow. Because the calculator builds this buffer in, its estimate reflects how a lender actually sizes your loan rather than the best-case figure a headline rate would imply.

This also explains why borrowing power can feel lower than you expect. If you calculate repayments at the advertised rate, the loan looks affordable, but the lender's buffered assessment produces a smaller maximum. Understanding this in advance prevents the disappointment of being approved for less than a simple repayment calculation suggested. It also highlights why the environment matters: when buffers or rates change, borrowing power moves even if your own finances have not.

The takeaway is to treat the buffered estimate as the realistic one. Planning around it, rather than around an unbuffered repayment figure, keeps your expectations aligned with what a lender will actually offer.

Improving your position before you apply

The calculator helps most by showing you which changes lift your borrowing power most. Because borrowing power comes down to your monthly surplus, anything that increases that surplus increases how much you can borrow. Reducing or closing credit card facilities is often the quickest win, since lenders count the full limit against you regardless of the balance. Clearing personal loans and other regular commitments frees up surplus directly.

On the income side, stable, verifiable earnings support a stronger assessment than irregular or uncertain income. Trimming ongoing discretionary expenses in the months before you apply can also help, both by improving your surplus and by presenting a cleaner spending picture. Test each of these in the calculator to see its effect, then focus your effort where it moves the number most. Finally, remember that this is a planning guide rather than an approval: a lender will verify your figures, apply detailed expense benchmarks and follow its own policy, so confirm your position with a lender or broker before committing to a purchase.

Common mistakes to avoid

• Borrowing the maximum. The top figure leaves no margin for rate rises or emergencies. Aim for a repayment you can sustain comfortably.
• Understating expenses. Optimistic expense figures inflate the estimate; lenders will use realistic benchmarks anyway.
• Ignoring credit card limits. Even unused limits reduce your capacity, so they are worth trimming before you apply.
• Treating the estimate as approval. Only a lender can approve a loan; use this as preparation, not a promise.

A borrowing power calculator helps you set a realistic budget, strengthen your position before applying, and avoid the disappointment of falling in love with a home you cannot finance.

This is general information, not financial advice. Confirm figures and rules with a qualified professional before making decisions.

About This Borrowing Power Calculator

Use this borrowing power calculator to get an instant, accurate estimate. The figures follow official guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.