Interest Rate Fixing Calculator

Compares two interest rates and terms to help you make decisions.

Enter a loan amount, a short-term rate, and a long-term rate.

Fixing at the "break-even" rate from the end of the short term, until the end of the long term, results in the same total interest paid as going with at the long term rate from the start.

How to use

  1. Enter two available rates — shortest term first.
  2. Enter a loan amount.
  3. Check the "break-even rate"
Months
Interest rate %
(a) Short term
mo
%
(b) Long term
mo
%
$ 300,000
Break-even rate
—
Interest Paid Breakdown
Initial 6 months interest  (short term rate) —
Remaining 6 months interest (break-even rate) —
Total interest over the period —
12 months interest at long-term rate —
Current NZ bank carded rates: interest.co.nz/borrowing/mortgages
Important
  1. This is neither financial nor lending strategy advice. The lowest rate is not always best. Discuss loan structures with a mortgage advisor.
  2. There are many approaches to lending, e.g. breaking a loan into a few smaller loans and fixing each for different lengths.
  3. The creators of this tool accept no liability for an adverse financial outcome due to your choice of lending rate or term.
  4. There are other reasons to fix long or short than the rate, such as flexibility around early repayments or certainty of outgoings.
  5. This tool does not consider a return on investing the money saved by paying lower interest for a period.