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Rental & ADU Payback (ROI) Calculator

Months to pay back an ADU, rental unit or rental purchase from net rent, plus yearly cash flow and cash-on-cash return.

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How this Rental ROI estimate works

This tool helps homeowners and small investors estimate how long it takes to recover the cost of building or buying an ADU or rental. It calculates your payback period and simple return based on your specific project costs and expected rent.

The calculator starts with your total project cost, which includes building or buying the unit. It then looks at your expected monthly rent. From that rent, it subtracts operating expenses, which default to 15 percent of the rent. It also accounts for vacancy, set at 5 percent by default. If you have a loan, you can add your monthly payment to the expenses. The tool uses these numbers to find your net monthly cash flow. It divides your total project cost by this net cash flow to find the months needed to pay back the investment. It also calculates your annual net cash flow and a simple cash-on-cost return. These figures are planning estimates only. They do not account for taxes, insurance changes, or market shifts. You should always confirm these numbers with a local professional before making financial decisions.

What drives the number

  • Your total project cost is the main starting point for the payback calculation.
  • Higher expected monthly rent increases your net cash flow and speeds up payback.
  • Operating expenses are deducted from rent, so a higher percentage lowers your net income.
  • Vacancy rates reduce the number of months you collect rent each year.
  • Loan payments are added to expenses, which can lower your monthly net cash flow.

Tips before you get bids

  • Use realistic rent estimates based on similar units in your area, not the highest possible price.
  • Include all operating costs like maintenance and management in your expense percentage.
  • Check your local zoning laws and permit costs before finalizing your total project budget.

Common questions

What is a simple cash-on-cost return?

This is a basic measure of your yearly profit compared to your total investment. It does not include complex financial adjustments or taxes. It is a quick way to see if the project makes sense on paper.

Why are the default expenses set at 15 percent?

This is a common starting point for planning purposes. It covers typical costs like maintenance and utilities. You should adjust this number to match your actual expected costs.

Does this calculator include property taxes?

No, this tool focuses on rent, operating expenses, vacancy, and loan payments. You should add property taxes and insurance to your expenses for a fuller picture.

Is this a guarantee of profit?

No, these are estimates for planning only. Real-world results depend on many factors like market conditions and maintenance issues. Always consult a local professional for accurate financial advice.

Put this Rental ROI calculator on your website

  • Shows your company name, logo and brand color
  • Visitors get an instant estimate and can request a quote
  • Copy-paste embed for most website builders
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