How it works
A quick "rent minus mortgage" check hides most of the cost of owning a rental. This calculator puts every monthly cost beside the rent so the real margin is visible.
Reserve lines for vacancy and maintenance cover costs that arrive irregularly; enter them as monthly dollar amounts.
Formula
(Rent + Other income) − All monthly expenses
Monthly expenses ÷ Monthly income × 100
Worked example
With the hypothetical defaults:
| Monthly surplus / deficit | -$347/mo |
|---|---|
| Monthly income | $2,400/mo |
| Monthly expenses | $2,747/mo |
| Annual surplus / deficit | -$4,164/yr |
| Expense-to-income ratio | 114.46% |
All figures in this example are hypothetical and chosen to illustrate the math. They are not current Houston market averages, quotes, or forecasts.
Frequently asked questions
Why reserve for vacancy if the property is leased?
Leases end. Reserving monthly spreads the cost of future vacancy and turnover across the year.
Is this the same as cash flow?
Essentially yes on a monthly basis, when every cost is entered.
See how every assumption interacts
The 713 Deal Generator combines financing, income, operating costs, and upfront cash into a printable report with stress tests and the 713 Metrics Score.
Run the Full 713 Deal Generator713 Metrics provides educational and informational tools based on user-provided assumptions. Results are estimates and do not constitute financial, investment, tax, legal, lending, appraisal, brokerage, insurance, or real-estate advice. Verify property-specific information independently and consult appropriate licensed professionals.