Rental Property Cash Flow Analyzer: Estimate Profit and Risk
Simple Rental Property Cash Flow Analyzer
This calculator helps you answer one practical question: Will this rental property produce positive cash flow each month? You enter rent, vacancy, expenses, and financing basics, and the calculator estimates monthly and annual cash flow plus a quick safety metric (DSCR).
Inputs Explained in Plain Terms
Monthly rent
Your expected rent before any vacancy or expenses.
Vacancy rate
Vacancy is the percentage of time you expect the unit to be empty or rent not collected. The calculator uses it to reduce rent into an effective rent.
Monthly expenses (total)
A single monthly number that includes everything you pay: taxes, insurance, HOA, repairs, management, utilities, and other recurring costs.
Financing basics
Down payment, interest rate, and loan term are used to compute a monthly mortgage payment using standard amortization.
How the Calculator Works
Effective rent
\( \text{EffectiveRentMonthly} = \text{MonthlyRent} \times \left(1 - \frac{\text{VacancyRate}}{100}\right) \)
Monthly cash flow
\( \text{CashFlowMonthly} = \text{EffectiveRentMonthly} - \text{MonthlyExpensesTotal} - \text{MortgagePaymentMonthly} \)
Annual cash flow
\( \text{CashFlowAnnual} = \text{CashFlowMonthly} \times 12 \)
Break-Even Rent
Break-even rent is the monthly rent needed to reach zero cash flow (given your vacancy, expenses, and mortgage payment):
\( \text{BreakEvenRentMonthly} = \frac{\text{MonthlyExpensesTotal} + \text{MortgagePaymentMonthly}}{\left(1 - \frac{\text{VacancyRate}}{100}\right)} \)
DSCR (Debt Service Coverage Ratio)
DSCR is a quick “safety” metric lenders commonly use. It compares annual net operating income to annual debt payments:
\( \text{DSCR} = \frac{\text{NOIAnnual}}{\text{DebtServiceAnnual}} \)
In this simplified version, annual NOI is estimated from monthly effective rent and monthly expenses:
\( \text{NOIAnnual} = (\text{EffectiveRentMonthly} - \text{MonthlyExpensesTotal}) \times 12 \)
Optional Advanced Expense Breakdown
If you prefer more detail, open Advanced options to break your expenses into parts. The calculator converts annual items to monthly and estimates percentage-based items (management and maintenance) based on collected rent. It then updates your total monthly expenses field so you can keep the simple view accurate.
How to Improve a Negative Cash Flow Result
- Increase rent or confirm market rent with comparable listings.
- Reduce expenses by re-checking taxes, insurance, HOA, and utilities you actually pay.
- Adjust financing using a larger down payment, lower interest rate, or longer loan term.
- Use conservative vacancy to avoid surprise out-of-pocket months.