Calculate your debt-to-income ratio for Australian mortgage applications. APRA monitors banks for high DTI lending — most lenders cap at 6×.
📖 14 min read · ⏱️ Calculator time: ~40 seconds
Adds a second, percentage-based DTI view using your actual monthly repayments, alongside the loan-to-income multiple above.
| Metric | Value |
|---|
Results are estimates only. Lenders assess many factors beyond DTI, and policies vary — confirm your borrowing capacity with a lender or broker.
APRA requires lenders to monitor loans with a DTI >6. While not a hard cap, loans with DTI >6 face increased scrutiny. Many lenders have internal policies limiting DTI to 6–8×.
DTI = Total debt / Gross annual income. Total debt includes: new mortgage + credit card limits (not balances) × 3.8 + other loans.
The debt-to-income ratio (DTI) measures your total monthly debt repayments as a percentage of your gross monthly income. Lenders use this metric to assess whether you have too much debt relative to your income to comfortably service a new home loan. A lower DTI indicates more financial breathing room and generally leads to more favourable loan terms.
In Australia, "DTI" is actually used to describe two related but different measures. The loan-to-income multiple (used prominently by APRA) expresses your total debt as a multiple of your gross annual income — for example, 6x. The repayment-to-income percentage expresses your monthly debt repayments as a percentage of your monthly income — for example, 35%. The calculator above computes both, since different lenders and commentators refer to either one as "DTI."
The loan-to-income multiple is calculated as: Total debt (new mortgage + existing loans + credit card limits) ÷ Gross annual income. The repayment-to-income percentage is calculated as: Total monthly debt repayments ÷ Gross monthly income × 100. Both use the same underlying inputs but express the result differently — a multiple (like 4.6x) versus a percentage (like 37.7%). Credit card limits (not balances) are typically assessed at around 3% per month as a standard industry convention, since the bank has to assume you could draw the full limit at any time.
DTI is one of the key metrics Australian lenders use to gauge serviceability risk — how likely you are to be able to keep up with repayments if your circumstances change or rates rise. A high DTI signals less buffer for the unexpected, which is why APRA monitors DTI concentration across the banking system and why individual lenders apply their own caps. That said, DTI is only one input among many — income stability, credit history, deposit size, and expenses all factor into a real lending decision.
| DTI Ratio | Interpretation | Australian Lender View |
|---|---|---|
| Under 28% | Excellent — low debt relative to income | Strong approval prospect, best rates available |
| 28% – 36% | Good — manageable debt load | Good approval prospect, standard rates |
| 36% – 43% | Borderline — under typical lender limits | May face additional scrutiny, some lenders decline |
| 43% – 50% | High — most mainstream lenders decline | May require specialist or non-bank lender |
| Above 50% | Very high — significant default risk | Most lenders will not approve |
APRA monitors DTI concentration risk across the banking system. Since 2021, APRA has been closely tracking loans with DTI above 6x (meaning total debt is more than 6 times your gross annual income). Many major banks now have internal policies limiting high-DTI lending as a proportion of their book, even if individual loan applications are otherwise sound.
The DTI multiple used in Australian mortgage assessment is typically expressed as total loan amount ÷ annual gross income. A $700,000 loan on a $120,000 income = DTI of 5.83x — below the 6x level that attracts regulatory attention. A $900,000 loan on the same income = DTI of 7.5x — in territory where many banks apply additional scrutiny or decline.
| Scenario | Monthly Income | Monthly Debts | DTI Ratio | Assessment |
|---|---|---|---|---|
| Clean profile | $8,000 | $2,000 (mortgage only) | 25% | ✅ Excellent |
| Mortgage + car loan | $8,000 | $2,500 (mortgage $2,000 + car $500) | 31.25% | ✅ Good |
| Multiple debts | $8,000 | $3,200 (mortgage + car + credit card minimum) | 40% | ⚠️ Borderline |
| High debt load | $8,000 | $4,500 | 56% | ❌ High risk |
| Debt type | How it's typically assessed |
|---|---|
| Mortgage (existing or proposed) | Full scheduled repayment, or loan-to-income multiple for the balance |
| Credit cards | ~3% of the total credit limit per month, regardless of balance |
| Personal loans | Full scheduled monthly repayment |
| Car loans | Full scheduled monthly repayment |
| HECS-HELP | Compulsory repayment based on income, deducted from assessable income |
| Buy Now Pay Later | Increasingly counted as an ongoing credit commitment by most lenders |
| Other loans (e.g. investment) | Full scheduled repayment, sometimes shaded for rental income offset |
When you're ready to apply, most Australian lenders will ask for the following to verify your DTI and full financial position:
| Metric | DTI | LVR | Serviceability |
|---|---|---|---|
| Measures | Debt vs Income | Loan vs Property Value | Ability to Repay |
| Used by | Lenders | Lenders | Lenders |
| Purpose | Borrowing Risk | Security Risk | Affordability |
These three metrics are assessed together, not in isolation — a strong DTI doesn't guarantee approval if serviceability (income minus expenses at the APRA-buffered rate) doesn't stack up, and a low LVR (large deposit) can sometimes offset a higher DTI in a lender's overall risk assessment.
| Term | Meaning |
|---|---|
| DTI (loan-to-income multiple) | Total debt divided by gross annual income, expressed as a multiple (e.g. 6x). |
| DTI (repayment-to-income %) | Monthly debt repayments divided by monthly gross income, expressed as a percentage. |
| Debt service ratio | Monthly debt repayments as a percentage of net (after-tax) monthly income. |
| Serviceability | A lender's assessment of your ability to afford loan repayments. |
| Serviceability buffer | An extra margin (commonly 3 percentage points) added to the test rate for affordability assessment. |
| Disposable income | Income remaining after tax and debt repayments. |
| Mortgage readiness score | A composite indicator combining DTI measures and disposable income into a single score. |
DTI is a genuinely useful lens on your borrowing position, but it's only one lens — the calculator above gives you both the loan-to-income multiple APRA tracks and the repayment-to-income percentage most lenders assess day to day, alongside a combined readiness score and practical ways to improve your position. Use the Improvement Simulator to see exactly how paying down a specific debt or adding income would move the needle, then pair this with our Borrowing Power and Mortgage calculators for the complete picture before you apply.
What is a good debt-to-income ratio for a home loan in Australia?
Most Australian lenders want to see a DTI (monthly debt repayments as a percentage of gross monthly income) below 36-43%. For the loan-amount-to-income multiple used by APRA, keeping total mortgage debt below 6x your gross annual income is the key threshold — loans above 6x receive increased regulatory attention and some lenders have internal caps.
How does debt-to-income ratio affect mortgage approval?
Lenders use DTI to assess whether your income can comfortably service your debts including the proposed mortgage. A high DTI either results in loan decline or requires the lender to apply additional scrutiny. You can improve your DTI by paying down existing debts, cancelling unused credit cards, or targeting a smaller loan amount.
Do credit card limits count in debt-to-income calculations?
Yes. Australian banks typically count 3% of your total credit card limit as a monthly repayment obligation, regardless of your actual balance. This is because the bank assumes you could spend up to the limit at any time. A $20,000 credit card limit adds $600 to your assessed monthly debt, increasing your DTI ratio.
What is the APRA DTI monitoring threshold?
APRA monitors banks' lending at DTI ratios above 6x (total debt more than 6× gross annual income). While 6x is not a hard limit, banks are required to report their concentration of high-DTI loans and most have internal policies limiting how much high-DTI lending they will do. A DTI of 5x-6x is generally the maximum for most mainstream lenders.
What is a debt-to-income ratio?
It's a measure of your total debt relative to your income, used by lenders to assess borrowing risk. In Australia it's expressed either as a multiple of annual income (e.g. 6x) or as monthly repayments as a percentage of monthly income (e.g. 35%).
How do I calculate my debt-to-income ratio?
Add up your total debt (mortgage + other loans + 3% of credit card limits), then divide by your gross annual income for the multiple, or divide your total monthly debt repayments by your gross monthly income for the percentage. The calculator above computes both automatically.
What is a good DTI ratio in Australia?
Generally, a loan-to-income multiple under 4-5x and a repayment-to-income percentage under 28-36% are considered strong. Above 6x (multiple) or 43% (percentage) attracts significantly more scrutiny from most mainstream lenders.
How does mortgage DTI differ from other loan DTI calculations?
The underlying concept is the same, but mortgage DTI typically includes the large proposed home loan balance, making the multiple version (total debt ÷ annual income) more commonly used than for smaller consumer loans, where the percentage version is more typical.
How is DTI used to assess borrowing capacity?
Lenders use DTI alongside a full serviceability assessment (income, expenses, the APRA rate buffer) to determine your maximum loan size. A high DTI can cap your borrowing capacity even if your income would otherwise support a larger loan.
What is a serviceability calculator and how does it relate to DTI?
A serviceability calculator estimates your maximum borrowing capacity using income, expenses and the APRA buffer — DTI is one output of that broader assessment, not a separate calculation. Our Borrowing Power Calculator models the full serviceability assessment.
How do lenders calculate DTI in Australia?
Most calculate total debt (existing loans + credit card limits at ~3%/month + the proposed new loan) divided by gross annual income for the multiple version, or total monthly repayments divided by gross monthly income for the percentage version. Exact methods vary by lender.
What counts as income in a DTI calculation?
Base salary is counted in full; overtime, bonuses and commissions are typically shaded to around 80% of their average; rental income is typically shaded to 75-80% of gross rent. Casual and contract income usually needs a consistent history to be counted at full value.
Does HECS-HELP debt affect my DTI?
Yes — the compulsory HECS-HELP repayment (calculated as a percentage of your income once above the threshold) is deducted from your assessable income, which flows through to a lower borrowing capacity and effectively a higher DTI for the same target loan.
Does Buy Now Pay Later affect my DTI?
Increasingly, yes. Many lenders now treat BNPL facilities like Afterpay or Zip as an ongoing credit commitment similar to a credit card, even though they don't charge interest, since they represent a recurring repayment obligation.
Can I still get a mortgage with a high DTI?
It's possible but more difficult — you may need a specialist or non-bank lender, a larger deposit, or to reduce your DTI first by paying down debt or increasing income. Some lenders have more flexible policies than others for the same DTI level.
Does DTI vary by lender?
Yes — while APRA sets system-wide monitoring expectations around 6x, individual banks set their own internal caps and risk appetite for high-DTI lending, which can differ meaningfully between lenders for the same application.
What is the difference between DTI and LVR?
DTI measures your debt relative to your income (a serviceability metric). LVR (Loan-to-Value Ratio) measures your loan relative to the property's value (an equity/security metric). Both are assessed independently in a loan application.
Can investment properties affect my DTI?
Yes — investment loan balances and repayments count toward your total debt, though rental income can partially offset this on the income side (typically shaded to 75-80% of gross rent).
How can I quickly lower my DTI before applying for a home loan?
Cancel unused credit cards (each $10,000 of limit can add roughly $3,600/year to your assessed debt), pay off small personal or car loans, and avoid taking on new BNPL commitments in the months before applying.
Does a co-borrower or partner's income lower our combined DTI?
It can, if their income is stronger relative to their own debts than yours, since DTI is calculated on combined income and combined debt. Adding a co-borrower with existing high debt can also raise the combined DTI, though.
What is a debt service ratio?
It's a close relative of DTI that expresses monthly debt repayments as a percentage of net (after-tax) income rather than gross income — giving a more real-world picture of the repayment burden against actual take-home pay. The calculator above shows both.
What is disposable income and why does it matter for a mortgage application?
Disposable income is what's left of your net income after debt repayments — it's the buffer you have for living expenses, savings and unexpected costs. Lenders want to see a healthy buffer remaining, not just a DTI below a specific threshold.
Is this calculator's mortgage readiness score an official lender score?
No — it's an educational indicator combining your loan-to-income multiple, repayment-to-income percentage and disposable income into a single 0-100 score, not a replacement for an actual lender's serviceability assessment.
How accurate is this DTI calculator?
It uses standard Australian industry conventions (3% of credit card limits, standard income shading) and is a solid planning estimate. Actual lender assessments vary in their exact methodology — always confirm your specific position with a lender or mortgage broker.
Does paying off my mortgage faster improve my DTI over time?
Yes — as your mortgage balance and repayment reduce, both the loan-to-income multiple and repayment-to-income percentage improve, which can make future refinancing or additional borrowing easier.
Can first home buyers use a DTI calculator?
Yes — it's especially useful for first home buyers to understand roughly how large a loan they might be approved for and where their existing debts (like a car loan or credit card) might be holding back their borrowing capacity before they start house-hunting.
Does self-employment affect DTI assessment?
Self-employed applicants are typically assessed on two years of tax returns and notices of assessment rather than payslips, with lenders adding back non-cash deductions like depreciation. This can affect the "income" side of the DTI calculation significantly compared to a PAYG employee.
Why do two different DTI numbers appear on this calculator?
The main result shows the loan-to-income multiple (total debt ÷ annual income, the measure APRA tracks), while the gauge below shows the repayment-to-income percentage (monthly repayments ÷ monthly income, the measure many lenders use day-to-day for serviceability). Both are legitimately called "DTI" in different contexts.
What happens if my DTI is above 6x?
It doesn't automatically mean rejection, but expect increased scrutiny, possibly a smaller approved loan amount, a request for a larger deposit, or referral to a specialist lending team — policies vary significantly by bank.
Does refinancing affect my DTI?
Refinancing itself doesn't change your DTI unless the new loan amount, rate or term changes your repayment, or you consolidate other debts into the new loan (which can lower your DTI by replacing multiple repayments with one, often smaller, combined repayment).