New Zealand calculator
Mortgage Repayment Calculator NZ
Estimate repayments for a New Zealand home loan using your balance, interest rate, term and repayment frequency. Compare principal-and-interest with interest-only and test extra repayments.
Last reviewed by NZ Calculator:
How are mortgage repayments calculated?
For a standard table mortgage, the repayment is based on the loan balance, interest rate, number of payments and repayment frequency. The formula sets a regular payment designed to reduce the balance to zero over the selected term if the rate does not change.
Your mortgage details
Your repayment estimate
This is a fixed-rate mathematical estimate, not a lender quote or borrowing-power assessment.
Mortgage repayment comparison
| Frequency | Estimated payment | Payments/year |
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How this mortgage calculator works
A standard table mortgage spreads principal and interest over a fixed number of payments. The calculator assumes the annual rate stays unchanged for the full term. Real New Zealand mortgages commonly refix, split across loan portions or use offset/revolving-credit structures, so use the result as a planning estimate.
Interest-only repayments
Interest-only mode estimates the interest due each period using the entered balance and rate. Because principal is not reduced, the outstanding balance remains at the original amount during the interest-only calculation.
Extra mortgage repayments
In principal-and-interest mode, the calculator can simulate a fixed extra amount added to every payment. Extra principal generally reduces future interest, but check your loan agreement for limits, fees or break costs.
NZ source: Consumer Protection — mortgages and home loans.
Frequently asked questions
How are mortgage repayments calculated?
For a standard principal-and-interest home loan, repayments are calculated from the loan balance, interest rate, number of payments and repayment frequency. This page uses the standard amortising-loan formula.
What will my mortgage repayments be?
Enter the loan amount, annual interest rate, term and repayment frequency. The calculator estimates the regular payment, total interest and total amount repaid if the rate stays unchanged.
Can I calculate weekly, fortnightly and monthly mortgage repayments?
Yes. Choose a repayment frequency and use the comparison table to see how the same loan looks at common repayment intervals.
Can I calculate an interest-only mortgage?
Yes. Interest-only mode estimates the interest payment during the selected period, but the principal is not reduced. It does not model a later switch back to principal-and-interest automatically.
Does this mortgage calculator show how much I can borrow?
No. It calculates repayments for a loan amount you enter. Borrowing power is a lender assessment that also considers income, expenses, existing commitments, security and lending criteria.
Can extra repayments reduce mortgage interest?
Usually, paying principal earlier reduces the balance on which future interest is calculated. Your contract may limit extra repayments or charge break fees, especially during a fixed-rate period.
Why might my bank's mortgage repayment differ?
Banks can use daily interest, different payment dates and rounding, fees, split loans, offset or revolving-credit structures, changing rates and contract-specific rules that this simplified calculator does not model.
Are mortgage repayments tax deductible in New Zealand?
Tax treatment depends on why the borrowing exists and your circumstances. This calculator does not provide tax advice. Check Inland Revenue guidance or obtain professional advice.