How are New Zealand mortgage repayments calculated?

Repayments use the standard amortising formula M = P·r(1+r)ⁿ / ((1+r)ⁿ−1), where P is the loan amount, r is the periodic interest rate, and n is the number of payments. Each repayment covers interest first, with the rest reducing the principal.

What deposit do I need in New Zealand?

Reserve Bank loan-to-value restrictions generally require owner-occupiers to have at least a 20% deposit (80% LVR) and investors at least a 35% deposit (65% LVR). Banks have limited capacity to lend above these limits, often at higher rates.

Are New Zealand mortgage rates fixed or variable?

Most New Zealand borrowers fix their rate for a term of 6 months to 5 years, then re-fix at the prevailing rate. A floating (variable) rate, which tracks the Official Cash Rate set by the Reserve Bank, is also available and is usually higher than short fixed rates.

Why do fortnightly repayments save interest?

Paying fortnightly using half the monthly amount means you make the equivalent of 13 monthly payments a year instead of 12. The extra payments reduce the balance faster, cutting total interest and shortening the loan.

Does this calculator store my data?

No. All figures are computed locally in your browser and nothing is uploaded, so your details stay private.

New Zealand Mortgage Calculator

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This New Zealand mortgage calculator models a standard amortising home loan and checks your deposit against the Reserve Bank loan-to-value (LVR) limits. Enter the price, deposit, rate and term to see monthly and fortnightly repayments and total interest.

How it works

Repayments use the standard annuity formula on the loan amount (price minus deposit):

M = P · r (1 + r)ⁿ / ((1 + r)ⁿ − 1)

where P is the loan, r is the periodic interest rate (annual ÷ payments per year), and n is the number of payments. The tool also computes your loan-to-value ratio = loan ÷ price, and flags it against the typical limits: 80% LVR (20% deposit) for owner-occupiers and 65% LVR (35% deposit) for investors.

A fortnightly schedule pays half the monthly amount every two weeks, which makes 26 payments a year — the equivalent of 13 monthly payments — so you pay the loan off sooner.

Example

Buy a NZD 800,000 home with a NZD 160,000 deposit (20%) at 6.5% over 30 years. The loan is NZD 640,000, the LVR is 80% (within the owner-occupier limit), and the monthly repayment is about NZD 4,045.

Notes

New Zealand has no general stamp duty on home purchases, so deposit and repayments are the main upfront and ongoing costs. Banks also apply a serviceability stress test, assessing whether you could afford repayments at a rate several percent above the actual rate. Lenders’ mortgage insurance is uncommon; instead, low-deposit lending is constrained by the LVR speed limits.