New Zealand housing calculator

The 19% Test

They paid 19%. Would you rather swap?

Enter your property address

Choose an official address. For Auckland properties, we'll try to find the latest council CV.

What is the property worth today? (editable)

No value loaded yet. Select an Auckland address to try the council CV lookup, or enter your own estimate.

Estimated historical value—Select an address and value

If it only kept up with inflation—Official NZ CPI adjustment

Adjust assumptions

Comparison year

Estimated historical value (editable)

Calculated from official housing-market HPI data after you select an Auckland address.

I know the actual historical value — keep my number

Deposit (%)

Today's rate (%)

19% world rate (%)

Mortgage term (years)

CPI adjustment

How this works & sources

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

Today's starting value: for Auckland, the calculator attempts to load Auckland Council's 2024 capital value as at 1 May 2024. It is a rating valuation, not a live market valuation, and you can edit it. Official / editable

Historical value: estimated using the Ministry of Housing and Urban Development Property & Sales Statistics House Price Index. Local-board HPI is used where available and chained to Auckland regional HPI for earlier years. 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 break-even rate is the interest rate on the inflation-adjusted historical price that produces the same initial monthly principal-and-interest payment as today's scenario.

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