Use the mortgage calculator above to estimate your borrowing power from your income, living costs, debts and deposit. You'll see an indicative borrowing range and purchase price. A lender still needs to check your documents and the property before approving a loan.
If you're working out the repayments on a particular loan, use the examples below or Moneysmart's mortgage repayment calculator. The tool at the top of this page estimates borrowing capacity; it doesn't have repayment-frequency or interest-only controls.
I would use the estimate to set an initial search range, then check whether the repayments leave enough room for the life you want to live. Our how much home can I afford guide takes you through that second check.
How to use this mortgage calculator
Have a recent payslip and a realistic picture of your spending handy. Work through the questions in this order:
- Your plans: choose what you're looking to do and whether the property will be your home or an investment. Refinancing and commercial enquiries need a separate assessment.
- Who is applying: select the household setup and number of dependants.
- Income: enter annual income before tax for each applicant. Keep overtime, bonuses, commission and rental income in the separate fields where relevant.
- Living costs: enter your monthly expenses, or use the modelled minimum for an initial estimate. Entering a low figure doesn't override the calculator's minimum allowance.
- Debts and commitments: include credit card limits, loan commitments and HELP student debt where applicable. Avoid counting the same expense twice.
- Buying plan: enter your state, first home buyer status and saved cash. The purchase-price estimate pays estimated stamp duty out of this cash before calculating the deposit available.
Open the assumptions and review the details you entered alongside the result. The calculator currently models a 30 year loan and a range of lending scenarios. It doesn't let you choose your own mortgage rate or proposed loan term.
For a new job or variable hours, use your year-to-date income as a cross-check. Don't enter your best pay week as if you earn that amount all year. A lender may average variable earnings or accept only part of them.
What do the borrowing range and purchase price mean?
The borrowing range estimates the loan amount under different assumptions. The midpoint is a starting figure for discussion, rather than an offer from a named bank. The estimated purchase price also considers your deposit, stamp duty and a maximum 95% loan-to-value ratio (LVR).
That purchase figure still needs a costs check. The model doesn't provide a lenders mortgage insurance (LMI) quote or a complete allowance for conveyancing, inspections and registration fees. It also doesn't add cash grants. A 95% LVR assumption doesn't confirm that you qualify for a 5% deposit loan.
Use our deposit calculator to compare deposit sizes and our LMI calculator to investigate mortgage insurance. Check the stamp duty guide and calculator for your state, or the NSW stamp duty guide if you're buying there.
If the estimate comes back low or shows no capacity, ask us to check the details before you rule out buying. How a lender counts your income, your existing debts and the proposed loan can change the answer.
How mortgage repayments are actually calculated
Principal and interest repayments depend on the amount borrowed, interest rate and time left to repay the loan. Part of each payment covers interest; the rest reduces the balance. As the balance falls, less interest is charged if the rate stays the same.
For example, a $700,000 purchase with $140,000 contributed towards the price leaves a $560,000 loan, before any financed costs. At an example rate of 6.25% p.a. over 30 years, that loan costs approximately $3,448 a month in principal and interest repayments.
Keep the purchase price and loan amount separate. Stamp duty and other buying costs need their own allowance; they don't disappear because you've saved a 20% deposit.
Monthly mortgage repayment examples
These examples use 6.25% p.a., a 30 year term and monthly principal and interest repayments. The rate is an illustration, not a current offer or forecast. Figures are rounded to full dollars and exclude fees, offsets, extra repayments and rate changes.
| Loan amount | Monthly repayment |
|---|---|
| $400,000 | $2,463 |
| $500,000 | $3,079 |
| $600,000 | $3,694 |
| $700,000 | $4,310 |
| $800,000 | $4,926 |
| $900,000 | $5,541 |
| $1,000,000 | $6,157 |
These are repayment calculations, not borrowing approvals. Two households on the same salary can qualify for different loan amounts because of their expenses, dependants and debts.
What affects how much you repay each month?
Interest rate
A higher rate raises the repayment required to clear the same debt over the same term. On a $600,000 loan over 30 years, increasing the example rate from 6.25% to 7.25% raises the monthly repayment from $3,694 to $4,093. That's approximately $399 more each month.
At 8.25%, the repayment would be approximately $4,508. Try the rate you've been quoted, then test rates 1 and 2 percentage points higher. Compare the result with your actual household budget before deciding what feels comfortable.
Loan size
A bigger deposit reduces the loan needed for a given purchase price. In the examples above, every extra $100,000 borrowed adds approximately $616 a month at the stated rate and term.
Keep some money available for moving, repairs and unexpected bills. Using every dollar of savings to lower the loan can leave you short immediately after settlement.
LVR and LMI
LVR compares the loan with the property value accepted by the lender. A 20% contribution will generally keep a straightforward purchase at or below 80% LVR if the valuation supports the price and costs aren't added to the loan. A lower valuation can change that calculation.
Lenders mortgage insurance (LMI) commonly applies above 80% LVR, unless you qualify for an exemption or waiver. It protects the lender. If you add its cost to the loan, you also pay interest on that extra borrowing. Our LVR calculator helps you check the ratio.
Eligible buyers can use the Australian Government 5% Deposit Scheme to purchase with a minimum 5% deposit without LMI. Location price caps, owner-occupier requirements and lender approval still apply. The guarantee doesn't give you a cash deposit or remove your repayments. See our first home buyer guide for the broader options.
Loan term
A shorter term increases the monthly repayment but reduces total interest if the other assumptions stay the same. For the $600,000 example at 6.25%, a 25 year term costs approximately $3,958 a month, compared with $3,694 over 30 years.
The extra $264 a month reduces total interest by approximately $142,544 across the loan, assuming the rate stays at 6.25%. Actual savings depend on future rates and how you repay. A term that only works while every household expense goes to plan may be too tight.
Principal & interest versus interest-only
Principal and interest repayments gradually clear the debt. Interest-only repayments cover interest for an agreed period, so scheduled payments don't reduce the original balance during that period.
The later repayment can rise because the principal must then be repaid over the remaining, shorter term. Compare both stages, including any difference in interest rates. Moneysmart's interest-only guide explains the trade-offs and links to a calculator for that comparison.
Fixed versus variable: which rate does the calculator use?
The borrowing tool uses its own modelled rates and assessment assumptions. It doesn't compare individual fixed and variable home loan products. For repayment calculations, enter the actual interest rate for the loan you're considering.
A fixed rate makes repayments more predictable during the fixed period. Check what happens when it ends, along with limits on extra repayments and possible break costs. A variable rate can change, and access to features such as an offset or redraw depends on the product.
Compare fees as well as the rate. The comparison rate includes certain fees using standard assumptions, so it helps you compare loans but doesn't replace a quote for your loan size and term. Our home loan guide explains how to compare the options.
For specific products, our NAB home loan review and Macquarie home loan review explain the features and fees to compare. Check the exact loan product before assuming it includes an offset or lets you make unrestricted extra repayments.
How lenders assess what you can actually borrow
A lender checks whether verified income can cover living expenses, existing commitments and the proposed mortgage. Credit history, employment and the property also matter. A calculator only covers part of that assessment.
For banks and other lenders regulated by the Australian Prudential Regulation Authority (APRA), the standard minimum mortgage assessment buffer is 3% above the actual rate. For example, a 6.25% loan would generally be tested at at least 9.25%, or a higher assessment floor where applicable. This is an assessment rate, not the rate you pay. Non-bank policies can differ. See APRA's current lending standard.
APRA also limits the share of new bank lending at debt-to-income ratios of 6 or more. This is a bank portfolio limit, rather than a blanket ban on an individual borrowing 6 times income. Passing a simple salary multiple doesn't establish approval. APRA's policy update sets out the distinction.
For your own estimate, pay particular attention to:
- Credit card limits: an unused card can still affect the assessment. Check with your broker before closing credit accounts you rely on.
- Variable income: overtime, commission and bonuses may need a history and may not be accepted in full.
- Living costs: lenders compare declared spending with their assessment allowances. The calculator's minimum is a model, not a budget recommendation.
- HELP and other debt: balances and repayments can affect the result. Read how HECS-HELP debt affects a home loan before using savings to repay it solely to increase borrowing.
I would check which of those items is limiting the loan before suggesting you save more or pay off a particular debt. The best use of the same $10,000 can differ from one household to another.
If HELP debt is part of that decision, our CommBank review explains its assessment approach. For a wider comparison, browse our bank and lender reviews once you know which income, deposit or loan features matter for your application.
Practical ways to lower your repayments (or pay off faster)
Use an offset account
With a $500,000 loan and $50,000 in a linked 100% offset, interest is generally charged on $450,000 while those balances remain. Your required repayment may stay the same, with more going towards principal.
Compare the likely interest saving with any extra rate or package fee. An offset with a small average balance may not justify a more expensive loan. Moneysmart's offset guide explains what to check.
Make extra repayments
Extra money paid towards principal can reduce future interest and bring the finish date forward. Check the product's rules first, especially during a fixed-rate period, and keep a cash reserve you can access.
Use our extra repayment calculator to model an amount you could keep paying. A regular commitment you can maintain is more useful than an ambitious number that leaves you short on bills.
Refinance when it makes sense
Compare the cost of switching with the saving over the time you expect to keep the loan. Include discharge and application costs, any fixed-rate break cost, and possible LMI on the new loan.
For example, $2,000 of switching costs divided by a $150 monthly saving gives a simple break-even point of about 14 months. That illustration assumes the saving continues and ignores timing differences. Compare loans over the same remaining term; restarting a 30 year term can lower repayments while adding to total interest. Our refinancing guide explains the next checks.
Shorten the term (if your cash flow allows)
Ask for a repayment comparison before committing to a shorter contractual term. You may prefer the flexibility of making extra payments on a suitable loan, subject to its rules. Either way, leave room for expenses that don't arrive every month.
Switch to fortnightly repayments
Check the amount, not just the frequency. Paying half the monthly repayment every fortnight produces 26 half-payments, equivalent to 13 monthly repayments each year.
If your monthly repayment were $3,000, paying $1,500 every fortnight would total $39,000 a year, compared with $36,000 paid monthly. But a lender could instead calculate a fortnightly amount that totals the same annual repayment. Merely changing the schedule doesn't guarantee that extra payment. Moneysmart's faster repayment guide explains the half-monthly approach.
Common mistakes to avoid
Treating the highest estimate as a spending target is an easy way to stretch the budget. Include rates, insurance, maintenance and strata levies where relevant, then keep some room for saving and life outside the mortgage.
Don't assume the calculator's purchase price includes every buying cost, or enter an advertised comparison rate as though it were the interest rate charged on the loan. And when comparing repayments, keep the loan size, term and repayment type consistent.
Before making an offer, work through the financing and contract conditions with your broker and solicitor. A borrowing estimate isn't pre-approval, and pre-approval itself still comes with conditions.
Mortgage calculator FAQs
How are mortgage repayments calculated?
Principal and interest repayments are calculated from the loan amount, interest rate, repayment frequency and term. At an example rate of 6.25% p.a. over 30 years, a $600,000 loan is about $3,694 a month, excluding fees. The borrowing tool above answers a different question: what loan amount your income and commitments might support.
How much deposit do I need for a home loan in Australia?
Some eligible borrowers can buy with a 5% deposit. A 20% deposit generally avoids LMI on a standard purchase when the lender's valuation supports the price. You also need buying costs and lender approval. Check the government scheme's eligibility or any LMI waiver before assuming the insurance cost is zero.
Is it better to make weekly, fortnightly, or monthly repayments?
Choose a schedule that fits your pay cycle, then check the annual total. Half a monthly payment made every fortnight adds an extra monthly payment over a year. A fortnightly amount calculated to keep the same annual total doesn't create that extra repayment automatically.
What's the difference between principal and interest versus interest-only repayments?
Principal and interest payments cover interest and gradually repay the balance. Interest-only payments don't reduce principal through scheduled repayments during the agreed period. Check the repayment after that period ends, when the remaining balance must be repaid over less time.
What interest rate should I use in the calculator?
For a repayment calculator, use a current quote for your circumstances and test higher rates too. The 6.25% examples on this page are illustrations. The borrowing tool above uses modelled assessment rates and has no editable interest-rate field; open its assumptions to see the basis of the estimate.
How much can I borrow?
Enter your income, expenses, debts and deposit into the tool for an initial range. A broker can then check the figures against lender requirements. Borrowing capacity is the loan amount; your purchase budget also depends on the deposit and buying costs. Your comfortable repayment limit may be lower than the maximum a lender would approve.
What happens if interest rates rise after I take out my loan?
Variable repayments may increase. A fixed rate usually protects the fixed portion during its agreed period, but the rate after expiry can be different. Allow some room in your budget and contact your lender early if repayments become difficult.
Does the calculator account for fees and charges?
The borrowing tool's purchase estimate allows for estimated stamp duty, but it isn't a complete settlement budget. It doesn't provide an LMI quote or include all legal, inspection and registration costs. The repayment examples on this page exclude fees entirely. Get a written costs breakdown for the property and loan you're considering.
Check your borrowing estimate and repayments
Bring us your estimate, deposit amount and the monthly repayment you'd be comfortable with. We can check how lenders may treat your income and commitments, and whether the property budget leaves enough cash for settlement.
Our Brisbane mortgage broker team can help you compare your options. You don't need to know which lender to choose before getting that check.
Sources and checks
Information checked on 12 September 2026. Repayment examples use the assumptions stated beside them and may differ from a lender's daily interest calculation. Calculator results remain estimates and don't confirm loan or scheme eligibility.
- ASIC Moneysmart: mortgage calculator and calculation assumptions
- ASIC Moneysmart: choosing a home loan
- ASIC Moneysmart: interest-only home loans
- ASIC Moneysmart: mortgage offset accounts
- ASIC Moneysmart: switching home loans
- ASIC Moneysmart: pay off your mortgage faster
- APRA: APS 220 Credit Risk Management
- APRA: mortgage buffer and debt-to-income policy update
- Australian Government 5% Deposit Scheme: first home buyer eligibility
- Reserve Bank of Australia: cash rate history