Rental Property ROI Calculator accuracy and testing

Formula source

• Rental property ROI = (annual cash flow + principal paydown + appreciation - capex reserve) / total cash invested x 100.

Test cases

Known limitations

• This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
• Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

• Appreciation is not guaranteed and is entirely user-entered.
• ROI is pre-tax and excludes depreciation deductions, sale costs, refinance costs, and transaction taxes unless reflected in entered values.
• All rents, expenses, rates, debt service, costs, appreciation, reserves, and investment amounts are entered by the user.
• Calculations run locally in your browser and are not stored by Calwarden.
• Results are estimates for planning and comparison only, not financial, tax, legal, lending, appraisal, or investment advice.

Unit handling

• Property Value accepts values in $.
• Gross Scheduled Income accepts values in $/yr.
• Other Income accepts values in $/yr.
• Vacancy Loss accepts values in $/yr.
• Operating Expenses accepts values in $/yr.
• Annual Debt Service accepts values in $/yr.
• Annual Principal Paydown accepts values in $/yr.
• Appreciation Rate accepts values in %/yr.
• Capex Reserve accepts values in $/yr.
• Total Cash Invested accepts values in $.
• Rental Property ROI is displayed as a percentage.
• Total Annual Return is displayed as currency.
• Annual Cash Flow is displayed as currency.
• Appreciation Amount is displayed as currency.

Rounding rules

• Number displays use up to 2 decimal places in the calculator UI.
• Currency outputs are displayed with standard US dollar formatting.
• Percent outputs are displayed with two decimal places.
• Input precision follows configured step values where provided.

Version history

Change log