Cap Rate
6.30%
Rental Property Calculator
Analyze cash flow, cap rate and cash-on-cash return for a rental property.
Monthly Cash Flow
$58.04
Cash-on-Cash Return
1.16%
NOI (Annual)
$18,900.00
Mortgage Payment
$1,516.96
How to use the Rental Property Calculator
The Rental Property Calculator is free and runs entirely in your browser — no sign-up, and nothing you enter leaves your device. It opens pre-filled with a realistic example, so you can see how it works before replacing any figure with your own; the results update as you type. Press Calculate to refresh the result panel, or Reset to return to the example.
The inputs it asks for:
- Purchase Price — a dollar amount.
- Down Payment — a dollar amount.
- Mortgage Rate — a percentage (enter 6 for 6%).
- Mortgage Term (yrs) — a number.
- Monthly Rent Income — a dollar amount.
- Monthly Operating Expenses — a dollar amount.
- Vacancy Rate — a percentage (enter 6 for 6%).
The formula
It works up from rent to the three numbers investors watch. Effective rent nets out vacancy; net operating income subtracts operating expenses; cash flow then subtracts the mortgage. Cap rate and cash-on-cash express the return against price and against cash invested:
NOI = (Rent·(1 − vacancy) − Expenses)·12
Cap rate = NOI ÷ Price Cash-on-cash = Cash flow ÷ Down payment- NOI
- net operating income — rental income after vacancy and operating costs, before the mortgage
- Cash flow
- NOI − annual mortgage payments
NOI deliberately excludes the mortgage (so cap rate compares properties regardless of financing); cash flow and cash-on-cash include it. It doesn't model income tax, depreciation, capital expenses or appreciation — all central to a full return picture.
Worked example
Using the example values — Purchase Price $300,000.00, Down Payment $60,000.00, Mortgage Rate 6.5%, Mortgage Term (yrs) 30, Monthly Rent Income $2,500.00, Monthly Operating Expenses $800.00, and 1 more — the Rental Property Calculator returns a Monthly Cash Flow of $58.04. It also reports Cap Rate (6.30%), Cash-on-Cash Return (1.16%), NOI (Annual) ($18,900.00).
Prefer your own numbers? Change any field above and this recomputes instantly.
Key terms
- NOI (net operating income)
- Rental income minus operating expenses, before financing.
- Cap rate
- NOI ÷ price — the unlevered yield, used to compare properties.
- Cash-on-cash return
- Annual cash flow ÷ cash invested — the levered cash yield.
- Vacancy rate
- The share of the year the unit is assumed empty.
Frequently asked questions
Cap rate vs cash-on-cash?
Cap rate ignores the mortgage (NOI ÷ price), so it compares properties on their own merits. Cash-on-cash counts the mortgage and measures return on the actual cash you put in.
What counts as operating expenses?
Taxes, insurance, management, maintenance and any utilities you pay — but not the mortgage (that's financing) and not capital improvements. Underestimating these flatters the result.
Does it include appreciation or tax?
No — it's a cash-flow snapshot. Long-run returns also come from appreciation, principal paydown and tax effects like depreciation, none of which are modelled here.