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Mortgage switching calculator

Compare the cost of switching your mortgage

Page reading time: 5 minutes

This calculator helps you work out:


  • This is a model not a prediction. Results are only estimates, the actual amounts may be higher or lower. We cannot predict things that will affect your decision such as movements in investment markets.
  • This calculator is not intended to be your sole source of information when making a financial decision. You should consider whether you should get advice from a licensed financial adviser.
  • This calculator is designed to help you see if switching home loans could be worthwhile for you. It is not intended to be relied on for the purposes of making a decision in relation to the financial product. You should consider obtaining advice from a financial services licencee before making any financial decisions.
  • Financial institutions all calculate interest and hence repayments in a slightly different manner, so the repayment patters produced by the calculator may not be the same for your loan.
  • Use of this calculator does not guarantee that you will be able to get a loan with the specified interest rates and fees. You will need to satisfy the lending criteria of whichever lender you are dealing with.
  • When comparing loans, changes in the cost of living over time have not been considered.


Interest rates

In making the calculations we assume the following:

      • the interest rates you enter are nominal and charged at the frequency you specify
      • each year has 12 equally sized months, 26 fortnights and 52 weeks
      • the introductory interest rate remains unchanged during the introductory period you specify
      • the ongoing interest rate remains unchanged at the ongoing rate for the remainder of the loan.

Up-front fees

Up-front fees (early termination fee, application fee, other switching costs) are added to the value of the loan at the start of the term.

Regular fees

Regular fees are charged at the end of each repayment period, prior to the repayment being made. If the regular fee frequency does not match the repayment frequency, then an equivalent fee for the repayment period is used.


Repayments are calculated so that the loan is paid off at the end of the specified term remaining. Where an introductory period has been selected, we calculate the repayments for this period assuming that the introductory rate applies for the entire term of the loan. At the end of the introductory period, we calculate a new payment level based on the loan outstanding and the remaining term at the time.

Results graph

Shows the savings generated by switching loans should you make the minimum repayments required under the existing loan to both loans. The saving plotted is the amount by which the amount outstanding on the new loan is less than what would have been owed on the existing loan at the same point in time. An adjustment is made in the last period to allow for the fact that a lower repayment may be required for the loan that is being repaid.