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Rental Property Calculator

Is this rental a good deal? Enter the numbers and see your monthly cash flow, cash-on-cash return, cap rate, and DSCR instantly — the same metrics lenders and serious investors underwrite on.

Quick answer: A rental is a good deal when four numbers agree: monthly cash flow is positive after every operating cost and the mortgage, cash-on-cash return beats what the same cash earns elsewhere (many investors screen at 8%+), cap rate is at or above local comps, and DSCR is at least 1.20–1.25 so a lender will finance it. Enter price, financing, rent, and expenses to get all four instantly.
The all-in purchase price of the property.
Percent of price you put down.
Annual mortgage rate. Ignored if you pay cash.
Usually 30 or 15 years.
Cash beyond the down payment: closing costs and any repairs.
Total monthly rent the property brings in.
Taxes, insurance, management, maintenance, vacancy, HOA — everything but the mortgage.
Monthly cash flow
Cash-on-cash return
Cap rate
DSCR
1% rule

Estimate only — a planning tool using the numbers you enter, not financial advice. Cash-on-cash counts your down payment plus closing and rehab as cash invested. For a full 5-year projection, BRRRR/refinance, and IRR, see the Deal Analyzer below.

No sign-up No ads Runs in your browser — your numbers never leave your device

How to tell if a rental property is a good deal

A good rental isn't about the price — it's about the numbers the property throws off. Four metrics tell you almost everything:

This calculator runs all four the instant you type. Enter a realistic operating-expense number — taxes, insurance, management, maintenance, vacancy — because understating expenses is the #1 way new investors talk themselves into a bad deal.

Watch: Is This Rental a Good Deal? The 4 Numbers Lenders and Investors Check

A 3-minute walkthrough of this calculator on a worked example — what each number means and the one that gets a deal declined. Narrated by an AI text-to-speech voice reading a script we wrote.

Plays from YouTube when you press play. Open on YouTube

How to read the four numbers this calculator gives you

Every rental analysis, from a first duplex to a lender's underwriting file, comes down to the same four figures. They answer different questions, and a deal can pass one while failing another, which is why you want all of them on one screen before you make an offer.

A worked example, using the calculator's default deal

Price $250,000, 20% down at 7% over 30 years, $21,000 of closing costs and rehab, rent $2,200, operating expenses $750 a month. The loan is $200,000 and the payment works out to about $1,331 a month. Cash flow is $2,200 − $750 − $1,331 = $119 a month, roughly $1,430 a year. Cash invested is $50,000 + $21,000 = $71,000, so cash-on-cash is about 2.0%. Net operating income is ($2,200 − $750) × 12 = $17,400, giving a cap rate of 7.0%. Annual debt service is about $15,970, so DSCR is 1.09. Rent-to-price is 0.88%, below the 1% rule.

That is a textbook marginal deal. The cap rate is respectable, which tells you the price is fair for the income. But the financing eats almost all of that income: 2% cash-on-cash loses to a savings account, and a DSCR of 1.09 is below the 1.20–1.25 most DSCR lenders require. The same property at $220,000 looks very different: the payment drops to about $1,171, cash flow rises to roughly $279 a month, cash-on-cash to about 5.2%, and DSCR to 1.24. Thirty thousand dollars of price is the difference between a deal a lender declines and one they fund.

The expense number decides everything, so do not guess it

The single most common way a rental analysis goes wrong is an operating-expense figure that only counts taxes and insurance. A realistic monthly figure includes property tax, insurance, a vacancy allowance (5–8% of rent is a common planning range), maintenance (5–10%), a capital-expense reserve for the roof, HVAC, and water heater (5–10%), management (8–10% if you will not self-manage), plus HOA and any utilities you pay. On a $2,200 rent those allowances alone run $500–$800 before tax and insurance. If your expense line is under 30% of rent on a long-term rental, you have almost certainly left something out.

Rules of thumb, and how far to trust them

Cash-on-cash targets vary by investor and market; 8%+ is a common screening bar, and anything under your mortgage rate deserves a hard look because the bank is earning more on the property than you are. Cap rates are only meaningful against local comparables: a 5% cap rate is strong in a top-tier metro and weak in a small market where 8% is normal. The DSCR floor of 1.20–1.25 comes from lender underwriting and is the one number that is not really up to you. The 1% rule dates from a 4% rate environment; at 7% it is a coarse filter at best, so treat a fail as “skip” and a pass as “now analyze it,” never as “buy.”

When this calculator is not enough

This tool prices one deal at today's numbers. It does not show what happens when rent grows 3% a year and expenses grow 4%, what depreciation does to your after-tax return, whether a refinance after a rehab gets your cash back out (the BRRRR question), or how the deal looks at sale in year five. Those are spreadsheet questions, and they are the reason the paid analyzer below exists: the Lite version adds a year-one after-tax view with depreciation and a rent-versus-price sensitivity grid, and the Pro version adds a five-year pro-forma, refinance and exit analysis, and stress tests. If you are comparing two or three serious candidates, that is the honest next step. If you just want this same screen as a spreadsheet you can keep, the free one-sheet deal screener does exactly that, no email required.

Quick FAQ

How do you calculate cash flow on a rental property?

Take gross monthly rent, subtract all operating expenses (taxes, insurance, management, maintenance, vacancy, HOA), then subtract the monthly mortgage payment. What's left is your monthly cash flow. This calculator does it automatically.

What is a good cash-on-cash return on a rental?

It varies by market, but many investors target 8% or higher. Cash-on-cash is your annual cash flow divided by the total cash you invested — down payment plus closing costs and rehab.

What is the 1% rule?

A 10-second screen: monthly rent should be at least 1% of the purchase price. It's a filter to decide what's worth analyzing, not a verdict — always run the full numbers before you buy.

What is DSCR and why do lenders care?

Debt-service coverage ratio is net operating income ÷ annual mortgage payments. Lenders use it to see whether the property's income covers its loan; most want 1.20–1.25 or higher for a rental loan.

Related: mortgage payment calculator · ROI calculator · DSCR calculator.

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More questions

Is the Rental Property Calculator free to use?

Yes. The Rental Property Calculator is completely free, runs in your browser, and never asks for a signup, email, or download. Enter your numbers and the result updates instantly.

How accurate is this calculator?

It uses standard formulas and recalculates the moment you change a value, so the math is exact for the inputs you enter. Treat the result as a reliable planning estimate; for decisions with legal or tax consequences, confirm the figures with a qualified professional.

Does it work on my phone?

Yes. The calculator is mobile-friendly and works on any phone, tablet, or computer — there is no app to install and nothing to save.

Can I add this calculator to my own website?

Yes. Scroll to “Add this free calculator to your site” above and copy the embed snippet to place the live calculator on your blog or website for free.

Last reviewed: September 2026. Free to use, no signup — Rental Property Calculator by ToolWise Digital.

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