Whether you’re buying a home or planning ahead, knowing your exact repayments on a $600,000 NZ mortgage is the first step in assessing affordability. The figures below use current indicative NZ mortgage rates and standard amortisation — the same method used by all major NZ banks.
On a $600,000 NZ mortgage at 5.50% over 30 years: weekly repayments are approximately $850, fortnightly $1,572, monthly $3,407. Total interest over 30 years would be approximately $626,424. A 25-year term increases repayments by about $278/month but saves $121,067 in total interest.
Repayments on a $600,000 Mortgage Over 30 Years
The table below shows weekly, fortnightly, and monthly repayments for a $600k NZ mortgage at a range of interest rates, on a 30-year term.
| Rate | Weekly | Fortnightly | Monthly | Total interest (30 yr) |
|---|---|---|---|---|
| 5.20% | $760 | $1,521 | $3,295 | $586,080 |
| 5.50% | $786 | $1,572 | $3,407 | $626,424 |
| 5.80% | $812 | $1,625 | $3,521 | $667,387 |
| 6.20% | $848 | $1,696 | $3,675 | $722,933 |
| 6.50% | $875 | $1,750 | $3,792 | $765,267 |
Rates shown are indicative for planning purposes. As of April 2026, major NZ bank 1–2 year fixed rates are approximately 5.2%–5.8%. Check current rates on the NZ mortgage rates page.
Repayments on a $600,000 Mortgage Over 25 Years
A 25-year term increases your monthly repayment but significantly reduces total interest paid.
| Rate | Weekly | Fortnightly | Monthly | Total interest (25 yr) |
|---|---|---|---|---|
| 5.20% | $826 | $1,651 | $3,578 | $473,343 |
| 5.50% | $850 | $1,701 | $3,685 | $505,357 |
| 5.80% | $875 | $1,751 | $3,793 | $537,837 |
| 6.20% | $909 | $1,818 | $3,939 | $581,848 |
| 6.50% | $935 | $1,870 | $4,051 | $615,373 |
Comparison at 5.50%:
- 30-year term: $3,407/month — total interest $626,424
- 25-year term: $3,685/month — total interest $505,357
- Saving by choosing 25 years: $121,067
The 25-year term costs approximately $278/month more but saves this substantial sum in interest. If your budget allows it, a 25-year term is worth considering.
Weekly vs Fortnightly vs Monthly Repayments
NZ banks offer weekly, fortnightly, and monthly repayment options. Fortnightly repayments save money and pay the loan off faster — this is because 26 fortnightly payments per year is equivalent to 13 monthly payments (one extra per year).
On a $600,000 mortgage at 5.50%, the fortnightly option versus monthly:
- Monthly: 12 payments × $3,407 = $40,881/year
- Fortnightly: 26 payments × $1,572 = $40,872/year
The fortnightly option directs approximately $-9 per year more to principal repayment, reducing the loan term by approximately 3–4 years and saving significant total interest.
The Impact of Extra Repayments
Making an additional $200 per week in extra repayments on a $600,000 NZ mortgage can reduce the loan term by approximately 3 years and save tens of thousands in total interest. Extra repayments go directly to reducing the principal balance, which reduces the interest charged each subsequent period.
Most NZ banks allow extra repayments on fixed-rate mortgages within a weekly limit (typically $500–$1,000/week) without triggering a break fee. On floating or revolving credit facilities, unlimited extra repayments are allowed.
What Income Do You Need for a $600,000 Mortgage?
Under the RBNZ’s DTI 6× cap, the minimum gross income needed to service a $600,000 NZ mortgage is:
- Sole borrower: $100,000 gross annual income ($$600k ÷ 6)
- Joint borrowers: Combined income of $100,000 gross
This assumes no other significant debt. Student loans, car loans, credit card limits, and personal loans all reduce the maximum mortgage available.
The bank’s serviceability stress test at approximately 7.5%–8.5% may also be the binding constraint for some borrowers.
Frequently Asked Questions
What are the repayments on a $600,000 NZ mortgage?
At 5.50% over 30 years: approximately $786/week, $1,572/fortnight, or $3,407/month. At 6.0%: $830/week, $1,660/fortnight, $3,597/month.
How much interest do I pay on a $600,000 NZ mortgage over 30 years?
At 5.50%, total interest over 30 years on a $600,000 mortgage is approximately $626,424. This reduces to approximately $505,357 on a 25-year term.
Is it better to take a 25 or 30 year mortgage for a $600,000 in NZ?
A 25-year term saves approximately $121,067 in total interest (at 5.50%) but requires about $278/month more. If your budget can comfortably handle the higher repayment, the 25-year term is the better financial choice.
What income do I need for a $600,000 NZ mortgage?
Under DTI 6×, you need at least $100,000 gross annual income (sole borrower) with no other significant debts. In practice, your actual serviceability assessment will also depend on living expenses and the bank’s stress-test rate.
Can I make extra repayments on a fixed NZ mortgage of $600k?
Yes — most NZ banks allow extra repayments of up to $500–$1,000/week on fixed-rate loans without a break fee. Check your specific loan terms. On floating rate mortgages, unlimited extra repayments are permitted.