Rental Property Calculator
Work out the net operating income, cap rate, monthly cash flow and cash-on-cash return of a rental property, with a mortgage included. It runs in your browser.
Also searched as: cap rate calculator · rental income calculator · cash on cash return calculator · investment property calculator
Updated November 9, 2026
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How to use it
- 1
Enter price and mortgage
Type the price, the down payment, the rate and the term.
- 2
Add rent and vacancy
Enter the monthly rent and how much of the year it may stand empty.
- 3
Add costs and read the results
Open More options for tax, insurance, upkeep and management.
Questions about rental property calculator
What is the cap rate?
Net operating income divided by the purchase price. It measures the return of the property before any mortgage.
What is cash-on-cash return?
The yearly cash flow after mortgage payments divided by the cash you put in, which is the down payment plus closing costs.
What costs are left out?
Income tax, big repairs and rent changes over time. Use the maintenance and vacancy options to allow for them.
From rent to cash flow
Take a 300,000 property bought with 20% down at 6.5% over 30 years, renting for 2,500 a month with 5% vacancy. After vacancy the rent collected is 28,500 a year. Property tax, insurance, upkeep and management take 8,505, leaving a net operating income of 19,995. That is a cap rate of 6.67%.
The mortgage payments are 18,204 a year, so the cash flow is 1,791 a year, or 149.29 a month. With 66,000 put in (the down payment and closing costs), the cash-on-cash return is 2.71%.
| Item | Per year |
|---|---|
| Rent collected after vacancy | 28,500 |
| Operating costs | 8,505 |
| Net operating income | 19,995 |
| Mortgage payments | 18,204 |
| Cash flow after mortgage | 1,791 |
What the ratios tell you
The cap rate ignores how the purchase is financed, so it is the one to use for comparing properties. Cash-on-cash return includes the mortgage, so it depends on the down payment and the rate. Here the monthly rent is under 1% of the price, which is below a common rule of thumb for screening, though many markets do not meet it.
Vacancy matters. Raising it from 5% to 10% cuts the monthly cash flow from 149.29 to 40.54. Income tax, big repairs and future rent changes are not included, so treat the result as a first screen before you look at real numbers.