DTI Calculator -- Debt-to-Income Ratio for NZ Mortgage Lending

DTI ratio measures your total debt as a multiple of your gross annual income. A DTI of 4.5x means your total debt is 4.5 times your annual income. RBNZ introduced DTI limits in 2024 to ensure borrowers don't take on unaffordable levels of debt.

The RBNZ DTI restrictions limit how much banks can lend at high DTI ratios. For owner-occupiers and first-home buyers, the limit is 6x gross annual income. For investors, the limit is 7x gross annual income. Banks have a small speed limit allowing a portion of new lending above these thresholds.

Divide your total existing debt by your gross annual income. For example, $500,000 of debt on a $100,000 income gives a DTI of 5.0x. This calculator does it for you -- just enter your income and total debt above.

Total debt includes your existing mortgage, personal loans, car loans, credit card balances, student loans, hire purchase agreements, and any other borrowings. Lenders will look at all debts on your credit report, not just housing-related debt.

You can improve your DTI by: (1) paying down existing debt, especially high-interest debt like credit cards and car loans, (2) increasing your income through a pay rise or second job, (3) consolidating debts to lower interest rates, or (4) choosing a lower purchase price to keep your total borrowing within the DTI limit.