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Rate Change Calculator

AustraliaScheduled modelClass B · rule-based estimateNo statutory rules requiredMethodology
AUD
Enter the annual rate as a percentage, like 5.99.

Repay interest only for the first years, then principal and interest.

The change applies from the first scheduled repayment on or after this date.

Enter your loan and the new rate to see the repayment change and lifetime effect.

Summary

Two ledgers run from the same loan: one where the rate changes on the effective date, one where it never moves. The repayment shown is the first scheduled repayment on or after that date.

Working

  1. §13.5 payment — the scheduled repayment solves P = B·i ÷ (1 − (1 + i)^−n) from the balance B, the periodic rate i and the remaining periods n.
  2. §13.7 recurrence — each period: interest = accruing balance × i, then closing = opening + interest + fees − payment − extra repayment.
  3. §13.9 offset — interest accrues on max(0, balance − offset × effectiveness), floored at zero; offset cash is never a principal repayment.
  4. §12.5.8 reconciliation — the ledger identity is checked on every period. A reconciliation failure invalidates the result rather than warning about it.

Assumptions

  • Interest accrues once per repayment period on the payment-period ledger. Daily accrual is not modelled at P0.
  • The first repayment falls on 1 October 2026; every date in the schedule follows from that and the repayment frequency.
  • The rate is held constant except where a dated rate-change event moves it.
  • Weekly, fortnightly and monthly frequencies use 52, 26 and 12 periods per year.

Limitations

  • Lender daily accrual, transaction timing, fee timing and rounding can differ from this model; compare the settings with your loan contract and statements.
  • Redraw availability, offset eligibility conditions, break costs and any lender fee that was not entered are not modelled.
  • Amounts beyond the entered term are not projected; a balance left unpaid at term is reported rather than extended.