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Property · New Zealand

Rent vs buy calculator NZ — guide and calculator

Compare the modelled cash costs and asset position of renting with buying over a chosen period.

Guide reviewed 20 August 2026 · Interactive calculator in development

Calculator in development

Interactive calculator coming soon. Full guide available now.

KiwiTools is building and testing the rent vs buy calculator. Everything below—the method, required information, worked example, assumptions, limitations and sources—is available now.

No estimated result is shown until the calculation is ready.

What this calculator will help with

The future calculator will expose assumptions for rent growth, mortgage costs, ownership expenses, returns and selling costs.

Use the result to compare clearly defined scenarios rather than as a prediction. Keep every other input unchanged when testing one decision so the effect of that change remains visible.

How the calculation works

Each scenario projects cash flows over time; buying also tracks loan principal and assumed property value, while renting can track investment of the cash difference.

The finished calculator will show the assumptions beside the result and will not silently substitute a personal rate, price, eligibility decision or future forecast.

Information to collect before calculating

Using your own current figures will normally produce a more useful scenario than relying on a generic default. Prepare these inputs:

  1. 1

    Rent, purchase price, deposit and mortgage terms

    Use a recent statement, bill, agreement, quote or measured figure where one is available. Keep the same basis when comparing alternatives.

  2. 2

    Rates, insurance, maintenance and transaction costs

    Use a recent statement, bill, agreement, quote or measured figure where one is available. Keep the same basis when comparing alternatives.

  3. 3

    Rent growth, property growth and investment-return assumptions

    Use a recent statement, bill, agreement, quote or measured figure where one is available. Keep the same basis when comparing alternatives.

Worked example

A five-year comparison can test the same household under conservative, middle and higher rent or property-growth assumptions.

This example demonstrates the method only. It is not a recommended setting, current market quote or estimate for a particular person.

Assumptions and limitations

  • Small assumption changes can reverse the comparison
  • Tax, market returns, repairs and personal flexibility are difficult to predict

The finished tool will provide a general planning estimate, not financial, legal, tax, lending or eligibility advice. Confirm decisions with the relevant provider or authority.

How to interpret the future result

Read the result as an estimate produced from the values entered. Compare a realistic base case with a cautious alternative, and check which input causes the largest change.

A useful result should help frame the next question. It does not verify an application, contract, tax position, product suitability or future price.

A simple comparison process

  1. 01Enter a realistic base scenario using the best information available.
  2. 02Change one uncertain input to create a cautious second scenario.
  3. 03Confirm changeable rules, rates and quoted costs with the linked source or provider.

New Zealand sources

These primary and reputable sources provide context for the method. Changeable rates and rules will be checked again before the interactive calculator launches.

Frequently asked questions

Is the rent vs buy calculator available yet?

The interactive calculator is still being built and tested. The method, inputs, example and limitations on this page are available now.

Will the result be exact?

No. Small assumption changes can reverse the comparison The finished calculator will show its assumptions and provide a planning estimate only.

Will this page address change when the calculator launches?

No. KiwiTools intends to add the calculator to this permanent page so saved links and the supporting guide remain in one place.

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