Formula and assumptions
Monthly compounding, equal principal-and-interest payments and a constant user-entered rate for the full term. Model version mortgage-amortisation-v1; reviewed 13 July 2026.
NZ mortgage repayment calculator
What would your home-loan repayments be each month?
Enter your proposed property price, deposit, loan term and a rate you want to test. The result is a transparent planning estimate—not a quoted rate, approval or personalised advice.
Your planning scenario
Enter your own rate; FHBG is not supplying a live lender rate.
Illustrative result
$3,792
estimated monthly principal-and-interest repayment
- Loan modelled
- $600,000
- Total interest over term
- $765,267
- Total repayments
- $1,365,267
Excludes lender fees, low-equity pricing, insurance, rates and ownership costs. It is not approval or advice.
Save questions about this scenarioWorked example
A $600,000 loan over 30 years at an illustrative 6.50% rate produces an estimated payment of about $3,792 per month. Change the rate to stress-test it.
Source and verification
Formula: standard loan amortisation mathematics. Rate inputs are yours. Confirm product terms with the lender and check the editorial method.
Mortgage repayment questions
How is the monthly mortgage repayment calculated?
The calculator uses the standard reducing-balance amortisation formula: payment = P × r × (1+r)^n ÷ ((1+r)^n − 1), where P is the loan, r is the monthly interest rate, and n is the number of monthly payments.
Does this use current New Zealand mortgage rates?
No. You enter a planning rate. Confirm current product rates, fees, repayment frequency and low-equity pricing directly with a lender or licensed adviser.
What costs are excluded?
The result excludes lender fees, low-equity margins or fees, council rates, insurance, maintenance and transaction costs. It is not a lender serviceability test or pre-approval.
Prepare for an offer
Use the offer guide to separate finance conditions from your price decision.
ContinueCompare suburb scenarios
Use the same repayment assumptions against alternative locations and prices.
ContinueSave FHBG request
Record lender-specific questions as a first-party request; this does not contact an adviser.
Continue