RentalDealMath

Rental Property Calculator

Enter a property's numbers once. See whether it pays for itself, what you earn on your cash, and how it could grow over 10 years. Free, no sign-up.

Purchase
$
%
$
$
Loan
%
yrs
Income
$
$
Parking, laundry, pets
Expenses
$
$
$
$
%
5% ≈ 18 empty days a year
%
0 if you self-manage
%
Of rent
%
Roof, HVAC, appliances
Growth (for the 10-year view)
%
%
%
–

–

    Monthly cash flow
    –
    Cash-on-cash return
    –
    Yearly profit ÷ your cash
    Cap rate
    –
    Profit before mortgage ÷ price
    Gross rental yield
    –
    Yearly rent ÷ price

    Where each month's rent goes

    More numbers

    What lenders and experienced investors check.

    Stress test

    How the deal holds up if things go worse than planned.

    ScenarioCash flow /moCash-on-cashResult

    10-year projection

    Equity in the homeTotal cash flow received
    YearHome valueLoan leftEquityCash flow that yearTotal return

    What these numbers mean

    Cash flow

    Money left each month after rent comes in and every cost goes out, including the mortgage. Negative means you pay out of pocket to keep the property.

    Cash-on-cash return

    Your yearly cash flow divided by the cash you put in (down payment, closing costs, repairs). Many investors look for 8% or more. Compare it to what your cash could earn elsewhere.

    Cap rate

    Net operating income (rent minus running costs, before the mortgage) divided by the price. It compares properties no matter how they're financed. Higher usually means more income but often a riskier area.

    DSCR

    Debt service coverage ratio: net operating income divided by yearly mortgage payments. Lenders for rental loans usually want 1.2 to 1.25 or higher.

    Break-even rent

    The lowest monthly rent at which the property covers all its costs. The bigger the gap between your rent and this number, the safer the deal.

    1% rule

    A quick screen: monthly rent at least 1% of the price. Hard to hit in expensive cities, so treat it as a rough filter, not a verdict.

    How to use this rental property calculator

    1. Enter the purchase details: price, down payment, closing costs and any repairs needed before renting.
    2. Add your loan: interest rate and term. Investment property rates are usually higher than rates for a home you live in.
    3. Enter the rent you expect, based on similar rentals nearby, plus any other income such as parking or laundry.
    4. Fill in expenses: property tax, insurance, HOA, and percentages for vacancy, management, repairs and big-ticket replacements.
    5. Read the verdict, then check the stress test to see whether the deal survives lower rent, higher rates or more vacancy.

    How we calculate the results

    These are the formulas behind every number, so you can check the math yourself.

    Net operating income (NOI)

    NOI = (rent + other income − vacancy) − operating expenses

    Operating expenses include property tax, insurance, HOA, utilities you pay, management, repairs and the big-ticket reserve. They do not include the mortgage.

    Cash flow

    Monthly cash flow = monthly NOI − mortgage payment

    Cash-on-cash return

    Cash-on-cash = yearly cash flow ÷ (down payment + closing costs + repairs)

    Cap rate

    Cap rate = yearly NOI ÷ purchase price

    Debt service coverage ratio (DSCR)

    DSCR = yearly NOI ÷ yearly mortgage payments

    Break-even rent

    The monthly rent at which cash flow is exactly zero, after vacancy, percentage-based costs and the mortgage.

    10-year projection

    Each year, rent grows at your rent growth rate, fixed expenses at your expense growth rate, and the home's value at your value growth rate. Equity is the home's value minus the remaining loan balance. Total return is the equity gained beyond your down payment plus all cash flow received.

    Frequently asked questions

    What is a good cash flow for a rental property?

    Many investors look for at least $100 to $200 a month per unit after every expense, including repairs, vacancy and a reserve for big-ticket items. What matters most is that the property stays profitable when rent drops or costs rise, which is what the stress test shows.

    What is a good cash-on-cash return?

    Many investors aim for 8% or more. Below 4% the margin is thin. Compare it with what your cash could earn elsewhere, and remember appreciation and loan paydown add to your total return.

    What is a good cap rate?

    Cap rates often fall between 4% and 10% depending on the market. Higher cap rates usually mean more income relative to price but can come with more risk or a weaker location.

    What is the 1% rule?

    A quick screen: monthly rent should be at least 1% of the purchase price. It is hard to meet in expensive markets, so treat it as a rough filter rather than a verdict.

    How much should I budget for repairs and vacancy?

    A common starting point is 5% of rent for repairs, 5% for big-ticket replacements like roofs and HVAC, and 5% to 8% for vacancy. Older properties usually need more.