Historical Mortgage Rates Analysis Calculator NZ 2026
This Historical Rates Analysis calculator analyses average historical monthly mortgage interest rates for both the RBNZ average floating rate and RBNZ average 2-year fixed rate going back to 1998. The historical data is profiled to determine the current rates comparative (percentile) ranking to all records before it. By ranking the rate and observing how it compares to the minimum, lower quartile, median, upper quartile and the maximum rate we can determine how it may change in short-medium term based on historical trends. The calculator also provides a recommendation based on the percentile ranking of the rank compared to the historicals for the class. If the rate is in the bottom 10% of all observed it's likely to be seen as unseasonably low by historical standards. The full assumption and groupings logic is available at below the calculator.
Enter your information into the calculator below, and push Calculate.
Deeper analysis
These extra measures use the same RBNZ floating and 2-year fixed series to show not just where rates sit, but which way they are moving, how unusual today is, and what it means in dollars. Past performance is not a guarantee of future results, and this is general information, not financial advice.
Floating vs fixed spread (the fix-or-float signal)
What it costs in dollars
Indicative principal-and-interest repayment on a $500,000 loan over 30 years at the 2-year fixed rate. Try your own figures in the mortgage calculator.
Historical Rate Percentile Distribution Scale:
This shows how the current rate compares to historical rates. If the rate in the bottom 10th percentile, it is ranked as 'Extremely Low' compared to historical rates.
<10% ="Extremely Low"
<20% ="Very Low"
<30% ="Low"
<40% ="Fairly-Low"
<60% ="Mid-Range"
<70% ="Fairly-High"
<80% ="High"
<90% ="Very High"
<=100% ="Extremely High"
Historical Rate Distribution Mid-Long Recommendation Scale:
Based on the rating, this recommendation below is based purely on the likelihood of rates normalising over time.
<10% ="Rates Very Likely To Rise"
<20% ="Rates Quite Likely To Rise"
<30% ="Rates Somewhat Likely To Rise"
<40% ="Rates May Rise"
<60% ="Rates Average Range"
<70% ="Rates May Drop"
<80% ="Rates Somewhat Likely To Drop"
<90% ="Rates Quite Likely To Drop"
<=100% ="Rates Very Likely To Drop"
NOTE: this analysis is meant as a guide only as past performance may not be indicative of future results. The dataset that this page uses is available from the Reserve Bank of New Zealand here.