Mortgage Calculator NZ: Calculate Your Repayments and Total Interest
How much will your mortgage repayments cost? Our calculator shows weekly, fortnightly or monthly payments, LVR, total interest, and savings.
Updated 14 June 2026
Summary
How to use the Mortgage Calculator
The calculator covers four common scenarios:
- Our Mortgage Calculator below shows the most important number in the home buying process - how much you will actually pay each week, fortnight, or month for the next 25 to 30 years.
- Beyond the headline payment, the calculator also reveals the figures most buyers never look at until it is too late, including the total interest you will pay over the loan term (often more than the property cost itself) and how dramatically extra repayments compound to reduce that total.
How to use the Mortgage Calculator
- Enter the property value and your deposit (or current equity if you already own the home).
- The calculator will work out the loan amount, your loan-to-value ratio, and the regular repayment for whichever frequency you choose.
- Add an extra repayment if you want to see exactly how much interest you would save and how much earlier you would pay off your mortgage.
The calculator covers four common scenarios:
- First home buyers: Enter the property price you are looking at and your KiwiSaver-plus-savings deposit. The LVR calculator shows whether you are above or below 80%, which is the key threshold most banks use to determine eligibility, low equity premiums, and lending restrictions.
- Refinancing or remortgaging: Enter your home's current value and the equity you have built up. The calculator will model the new loan against your remaining term and the rate you are considering.
- Investors: Enter the property price and your investor deposit (typically 20%+ to 35% as required by most banks). Results are net of any rental income, which the calculator does not model.
- Already have a mortgage: Enter your current property value and your current equity, set the term to your remaining years, and use the extra repayment field to see how much interest you can save by increasing your payments.
Your mortgage details
Loan amount
$600,000
LVR
80%
Payment frequency
Loan type
Your fortnightly repayment
$0
Principal & Interest
Total interest
$0
Total cost
$0
Pays off in
0 years
Principal and interest over time
Principal paid
Interest paid
| Year | Principal paid | Interest paid | Total paid | Balance remaining |
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Calculator assumptions
This calculator uses the standard amortisation formula used by all New Zealand banks. The headline repayment figure assumes:
Important to know: Results are illustrative projections, not a loan offer. Actual repayments depend on your bank's specific terms, any fees that apply, and your individual circumstances. RBNZ loan-to-value ratio restrictions and bank serviceability tests apply on top of the calculations shown here. Speaking with a mortgage broker or your bank will give you the most accurate picture of what you can actually borrow.
This calculator uses the standard amortisation formula used by all New Zealand banks. The headline repayment figure assumes:
- A constant interest rate for the full loan term (in practice, most NZ home loans are fixed for one to five years and then re-fixed at the prevailing rate)
- Equal repayments throughout the loan term, with each payment containing both principal and interest
- No fees, lender charges, or low equity premiums included in the calculation
- Extra repayments are made every period (weekly, fortnightly or monthly, matching your chosen payment frequency) and continue until the loan is repaid
- Interest Only mode shows the interest-only payment for the term you select; the loan principal remains unchanged at the end of the IO period, and would need to be either repaid in full or refinanced into a Principal & Interest loan
Important to know: Results are illustrative projections, not a loan offer. Actual repayments depend on your bank's specific terms, any fees that apply, and your individual circumstances. RBNZ loan-to-value ratio restrictions and bank serviceability tests apply on top of the calculations shown here. Speaking with a mortgage broker or your bank will give you the most accurate picture of what you can actually borrow.
Frequently Asked Questions
Should I choose a fixed or floating mortgage rate in New Zealand?
Most New Zealand mortgages are fixed for one to five years rather than floating (variable). Fixed rates protect you from interest rate rises during the fixed period and make your repayments predictable, which matters when you are budgeting for the long term. Floating rates are typically higher than fixed rates but allow you to make unlimited extra repayments and pay off the loan early without break fees.
The standard approach for most New Zealand borrowers is to fix the bulk of the loan for one to two years, sometimes splitting it across multiple fixed terms to spread the rate risk, and keep a smaller floating portion (or offset it against savings) for flexibility. The right strategy depends on how comfortable you are with rate uncertainty and whether you plan to make significant extra repayments.
Talking to a mortgage broker is usually worth it for this decision because the structure choice can save or cost tens of thousands of dollars over the loan term. You can see the latest mortgage rates in our guide.
The standard approach for most New Zealand borrowers is to fix the bulk of the loan for one to two years, sometimes splitting it across multiple fixed terms to spread the rate risk, and keep a smaller floating portion (or offset it against savings) for flexibility. The right strategy depends on how comfortable you are with rate uncertainty and whether you plan to make significant extra repayments.
Talking to a mortgage broker is usually worth it for this decision because the structure choice can save or cost tens of thousands of dollars over the loan term. You can see the latest mortgage rates in our guide.
What is a low equity premium and how does it affect my mortgage?
A low equity premium (LEP) is an additional fee or higher interest rate that most NZ banks charge when your loan-to-value ratio exceeds 80%, meaning your deposit is less than 20% of the property value.
The premium typically adds between 0.25% and 1.50% to your interest rate, depending on your LVR and the bank you use. On a $600,000 loan over 30 years, a 0.50% rate increase costs roughly $200 per fortnight in extra repayments and adds about $90,000 to total interest paid over the loan term.
The premium drops or disappears once your LVR falls below 80%, either because you have paid down enough principal or your property has appreciated. Some banks will refund or remove the premium automatically once you cross the threshold; others require you to apply. It is worth asking your bank about its LEP policy, both when you take out the loan and as your equity grows over time.
The premium typically adds between 0.25% and 1.50% to your interest rate, depending on your LVR and the bank you use. On a $600,000 loan over 30 years, a 0.50% rate increase costs roughly $200 per fortnight in extra repayments and adds about $90,000 to total interest paid over the loan term.
The premium drops or disappears once your LVR falls below 80%, either because you have paid down enough principal or your property has appreciated. Some banks will refund or remove the premium automatically once you cross the threshold; others require you to apply. It is worth asking your bank about its LEP policy, both when you take out the loan and as your equity grows over time.
How do I refinance my mortgage to a lower interest rate?
Refinancing means moving your mortgage to a new lender (or sometimes negotiating with your existing lender) to secure a lower rate or better terms. The process is straightforward - typically you get a few competitive rate quotes, calculate any break fees on your existing fixed loan, calculate the net saving over the new loan term, and apply with the new lender. Most banks offer cashback contributions of $1,000 to $5,000+ to incentivise switching, which can offset some of the costs.
The main hurdles are break fees on fixed-rate loans (which can be substantial if interest rates have fallen significantly since you fixed), legal fees of around $1,000 to $1,500 to register the new mortgage, and the time required to gather updated income and property documents.
Refinancing is most often worthwhile if you can reduce your rate by 0.5% or more, or if your current loan is close to the end of its fixed term so break fees are minimal. Our Mortgage Refinance Calculator can help you crunch the numbers before you commit.
The main hurdles are break fees on fixed-rate loans (which can be substantial if interest rates have fallen significantly since you fixed), legal fees of around $1,000 to $1,500 to register the new mortgage, and the time required to gather updated income and property documents.
Refinancing is most often worthwhile if you can reduce your rate by 0.5% or more, or if your current loan is close to the end of its fixed term so break fees are minimal. Our Mortgage Refinance Calculator can help you crunch the numbers before you commit.
Should I contact a bank or talk to a mortgage broker?
Mortgage brokers are popular and don't charge a fee. Their service goes beyond what a bank offers by comparing a number of lenders to find the best deal for your circumstances.
We've shortlisted top-rated mortgage brokers who go the distance for their clients in select cities around New Zealand:
We've shortlisted top-rated mortgage brokers who go the distance for their clients in select cities around New Zealand:
How much should I borrow to buy a house?
General practice suggests spending no more than 25% to 30% of your monthly gross income on your mortgage. For example, if you earn $80,000 a year, that's around $1,667 to $2,000 per month. This leaves you money for essential expenses and everyday items, such as living costs, house repairs and insurance, council rates bills, utilities and any body corporate charges. Check our how much can I borrow mortgage affordability calculator for more details.
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This calculator is supported by LifeDirect Mortgages, our 2026 Editor's Choice for nationwide mortgage advisers. LifeDirect Mortgages' experienced team makes the home loan process simpler, faster, and stress-free for first-home buyers, those refinancing, and property investors alike.
They also offer a useful Mortgage Potential Calculator that gives you a clear snapshot of your borrowing ability in seconds (no personal information required), showing your estimated borrowing amount, weekly/fortnightly/monthly repayments, and tips to improve your mortgage readiness. We encourage you to contact their friendly experts to discuss your mortgage needs - you can learn more about LifeDirect Mortgages with our detailed review or visit their website. |
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