New Zealand · NZD · Mortgage and repayment

Interest-Only and Repayment Transition

Published by REO Technologies · Publisher contact: Abdul Raheem. Explanation and example arithmetic revised 2026-10-26; source-specific dates are stated separately. No licensed financial review is claimed.

Compare interest-only principal, repayment from outset and a later P&I transition.

Enter current figures from your documents and quotes. Budget settings are editable. Inputs stay in this tab and are not saved or sent by the calculator.

Reference scope documented 2026-10-25. Use actual quotes and provider-confirmed amounts. KiwiSaver standard rates changed in April 2026; old grant and insurer assumptions are not applied. RBNZ lending-flow controls are not personal approval rules.

Your inputs

How this estimate works

Interest-only payment = principal × annual rate / 12. Later P&I repays the same principal over the shortened remaining repayment period at an unchanged assumed rate.

Assumptions and limits

Amounts are NZD. Enter actual current rates, balances and cost quotes; no bank offer or personal eligibility is invented.
Constant-rate monthly nominal model or an explicitly labeled equivalent-period scenario. Actual daily accrual, payment dates, fees, rate fixes and lender rounding can differ.
Educational arithmetic only. Provider, lender, IRD, tenancy and legal eligibility need independent confirmation. A repayment period differs from a fixed-rate deal period.
No capital repayment strategy, future rate or refinance approval is guaranteed.

References and further reading

Worked New Zealand example: Interest-Only and Repayment Transition

This is a hypothetical arithmetic example in NZD, not a current lender quote, market observation or borrower record. The same calculator model produces the figures below. Its input assumptions are shown so that you can reproduce or change the scenario.

Assumed input	Illustration value
Current / proposed mortgage principal (NZD)	520,000
Actual / scenario annual nominal rate (%)	5.99
Remaining repayment years	30
Interest-only years before repayment	5

Calculated measure	Result
Interest-only monthly payment	NZ$2,595.67
Repayment payment from outset	NZ$3,114.32
Interest-only principal after entered period	NZ$520,000.00
Repayment-model balance at same point	NZ$483,822.82
P&I after interest-only period, at unchanged rate	NZ$3,347.19

Amounts use unrounded intermediate arithmetic and are rounded only for display. Selecting different costs, rates, payment dates or terms changes the result; no illustration value is prefilled into your personal financial fields.