Mortgage repayments, and the rate you are tested at
The repayment you make and the repayment the lender tests you on are two different numbers.
Monthly repayments at example rates
| Loan | At 5.5% | At 6.0% | At 6.5% | Tested at 9.0% |
|---|---|---|---|---|
| $400,000 | $2,271 | $2,398 | $2,528 | $3,218 |
| $500,000 | $2,839 | $2,998 | $3,160 | $4,023 |
| $550,000 | $3,123 | $3,298 | $3,476 | $4,425 |
| $600,000 | $3,407 | $3,597 | $3,792 | $4,828 |
| $700,000 | $3,975 | $4,197 | $4,424 | $5,632 |
| $800,000 | $4,542 | $4,796 | $5,057 | $6,437 |
Monthly principal and interest repayments over 30 years. The rates are examples to show the mechanics, not rates on offer. Use the repayment calculator for your own loan.
Why the last column matters
A lender must check you could still afford the loan if rates rose by 3 percentage points. On a 6% loan that means being tested at 9%. For a $550,000 loan the test repayment is about $1,128 a month higher than the real one. Your income has to cover the test figure, plus living expenses and other debts.
What moves the repayment
- Rate. On $550,000, each 0.25% is roughly $1,375 a year in interest.
- Term. A shorter term lifts the repayment and cuts the total interest.
- Frequency. Paying half the monthly amount every fortnight adds up to one extra monthly repayment a year.
- Offset. Savings in an offset account reduce the interest charged. How offsets work.
Questions people ask
What share of income should go to repayments?
There is no single rule. A common guide is to stay under about 30% of income before tax, but your other costs and plans matter more than a ratio.
General information, last updated November 2026. Scheme figures, lender policies and duty rates change, so confirm them before you rely on them.
Keep reading
Let’s talk about your next move
Twenty minutes on the phone. No documents and no sales pitch.