Property Investment Calculator

$40.00 NZD
Approx $24.63 USD

Blurb: Project year-on-year cashflow and equity growth, Return on Investment and Return on Equity for your rental property over the next 15 years with our calculator tool. Including interest-only and P&I loan scenarios.


About the Property Investment Calculator

(NEW) Updated for the interest deduction rules introduced in 2021
We are now sending 2 versions of the calculator.

  • A calculator where you can specify the % of your interest that is tax-deductible. For new builds you would put 100%, for a property where part of your borrowing costs are tax-deductible you can set a lower %.
  • For properties owned prior to March 27, 2021, a version that phases out interest as a tax deduction over a few years and you can specify the % of your interest that is tax deductible for each of the first 4 years in the calculator.

These are estimates and we encourage investors to review their tax position with a qualified accountant. 


Understanding the numbers is the most critical part of your decision process when buying an investment property.  Unfortunately most people spend very little time looking at the cashflows and financials of a property.

Whether you’re buying your first rental property or you have a number of properties, you can use this calculator to help you do the sums.

How it works

You type in figures such as:

  • Purchase price
  • Loan amount
  • Interest rate
  • Various annual costs such as rates, insurance, maintenance, etc
  • Rental income
  • Property management cost
  • Chattels value estimate (explained with an attachment)
  • Annual expected % increases in capital growth and rent.
  • Likewise annual expected % increases in ongoing costs
  • Tax rate

The calculator will (over a 15 year period):

  • Show you how much of the rent will cover the costs of owning the property and how much you will need to contribute (or what the positive cashflow is)
  • Compare the Interest Only and Principal and Interest repayment costs
  • Show you the effect of different levels of deposit 
  • Show you what spending on a renovation will mean for your ongoaing cashflow and equity return
  • Give you an estimate of your potential tax changes (rebate or extra payment)
  • Work out the Gross Cashflow (before tax) and Net Cashflow (after tax)
  • Project your capital growth and cashflows forward15 years
  • Allow you to manually allow for capital growth and expense increases
  • Work out your true Return on Investment over time as well as year-on-year

The iFindProperty Calculator is very easy to use and provides a one page financial projection estimates for a property going 15 years into the future. For final and accurate projections and an understanding of your tax liability you should always speak with a qualified accountant. 

System Requirements:
The calculator was made in Microsoft Excel. It has been tested on modern versions of Excel for Windows & Mac