New Zealand housing calculator

The 19% Test

Ever been told how hard homeowners had it in 1989, when mortgage rates hit 19%?

So, who would actually be better off?

🏠 1989 house prices at 19% interest
or
🏠 Today’s house prices at 5% interest

Enter your address below and we’ll tell you.

Choose an official address. Where public council valuation data is available, we'll load it automatically. Everywhere else, you can enter today's value and still run the test.
We'll use public council valuation data where available. If we can't find one, enter your estimate of today's value — the test still works anywhere in New Zealand.
See the numbers & adjust assumptions
Starts with a public council CV where available. Change it if you have a better current estimate.
Calculated from official housing-market HPI data for the property's local authority.
How this works & sources

Address: matched against the official LINZ NZ Addresses dataset. Official

Today's starting value: the calculator attempts to load a public council capital/rating value where an integrated council data source is available. It is a rating valuation, not a live market valuation, and you can edit it. If automatic valuation data is unavailable, you can enter today's value yourself. Official / editable

Historical value: estimated using the official Property & Sales Statistics House Price Index. Auckland uses Local Board HPI where available; elsewhere the relevant Territorial Authority HPI is used. This is an estimate, not an individual historical valuation, and can be overridden. Estimated

Inflation-only value: the historical value is increased using NZ CPI from the RBNZ M1 series (source: Stats NZ), using June 2026 CPI of 1359. Official

Mortgage comparison: both scenarios use the same deposit percentage and mortgage term. The main result simply compares today's monthly repayment with a 19% mortgage on the inflation-adjusted historical price.

Scope: The 19% Test compares initial mortgage repayments and deposit requirements. It does not compare wages, taxes, household expenses or affordability over the full life of the mortgage.

This is an illustrative affordability comparison, not financial advice or a property valuation.