What is the debt-to-income ratio cap in Australian mortgages?
Australia's debt-to-income (DTI) ratio cap limits total debt across all loans to 6 times your gross annual income. If you earn $100,000, your maximum total debt is $600,000. Existing debts — mortgages, car loans, and credit card limits (treated as fully drawn regardless of actual balance) — all count against this cap. HECS/HELP has been excluded since 30 September 2025.
How it affects your borrowing
For many borrowers, DTI is not the binding ceiling — serviceability often limits first. But for higher-income earners with existing debt, or borrowers building a property portfolio, DTI frequently becomes the cap. Credit card limits are the most overlooked factor: a $30,000 limit you never use still reduces your mortgage ceiling by $30,000.
Worked example
Key factors
- Credit card limits are counted in full regardless of actual balance — reducing or closing cards before applying can meaningfully increase your ceiling.
- HECS/HELP is excluded from DTI since 30 September 2025 per APRA direction.
- Investment property mortgages count against DTI even if the property is positively geared.
- The 6× cap is a practical market ceiling — APRA guidance, not a hard legislative limit, but major banks all apply it.
See how this affects your specific situation
Check your DTI ceilingFrequently asked questions
Is the 6× DTI cap a legal requirement?
Not a hard legal cap — APRA sets macro-prudential guidance rather than a fixed limit. But mainstream lenders have aligned on 6× as their practical ceiling. Applications above this are typically declined at major banks.
Does DTI apply per borrower or combined?
Combined. For joint applications, total debt is compared to combined gross income. Two borrowers on $80,000 each have a combined cap of $960,000.
How do I reduce my DTI?
Close or reduce credit card limits — this is the fastest lever. Pay down consumer debt before applying. Increasing income (or adding a co-borrower) raises the cap directly.
What counts as debt in the DTI calculation?
Mortgage balances on all properties, credit card limits in full, car loans, personal loans, and BNPL balances if declared. HECS/HELP is excluded since September 2025.
This page is part of GetReal's methodology documentation. Figures are updated when underlying data in our Supabase database changes. This is not financial advice.