Rental Property Calculator
Cash flow, cap rate, cash-on-cash return and profit at a glance.
Property Purchase
Monthly Cash Flow
Understanding the metrics
- Cash Flow — rent collected after vacancy, minus tax, insurance, maintenance, management and mortgage. Positive is the goal.
- Cap Rate — operating income before mortgage divided by price. Best for comparing properties without financing.
- Cash-on-Cash Return — annual cash flow divided by your cash investment (down payment + closing costs).
- Total Return / Profit — includes cash flow over the holding period plus the gain on sale after appreciation and selling costs.
Rental Property FAQ
On this page
Rental Property Calculator — analyze any income property
Professional landlords analyze rentals with cash flow, cap rate and cash-on-cash return. This calculator runs those numbers for you — rent minus mortgage, tax, insurance, maintenance and vacancy — so you know whether the property makes money before you commit.
The key rental metrics
Net operating income (NOI) = gross rent − vacancy − operating expenses (before mortgage).
Cap rate = NOI ÷ property price × 100 — the unleveraged return. 4–6% is typical for residential in metros.
Cash-on-cash = annual cash flow ÷ down payment × 100 — measures the return on YOUR money after financing.
The 1% and 50% rules
1% rule: monthly rent should be at least 1% of purchase price (e.g. $3,000 rent on a $300,000 property). Many high-demand housing markets fall short — the rule is a filter, not a law.
50% rule: roughly 50% of gross rent goes to vacancy, maintenance, taxes and insurance (before mortgage).
If cash flow is negative month one, it rarely self-corrects without appreciation — run the numbers cold.
How to use this calculator
- Enter the purchase price and down payment.
- Enter your mortgage rate and term.
- Enter expected monthly rent.
- Add expenses: property tax, insurance, maintenance, vacancy.
- Read your monthly cash flow, cap rate and cash-on-cash return.
Pro tips
- Budget 1–2% of property value annually for maintenance.
- Check the local tenant market — vacancy months hurt cash flow badly.
- Keep a 6-month buffer of mortgage payments for vacant periods.