Rental Property Cash Flow Calculator
Analyze any rental property in seconds. Enter the purchase price, your financing, the rent, a vacancy rate, and your operating expenses, and this calculator shows your monthly cash flow, cash-on-cash return, cap rate, NOI, DSCR, and more — so you can tell whether a deal actually puts money in your pocket. Several inputs can be entered as a percent of rent or a flat dollar amount, and you can share a link or export a PDF of your analysis. It's a clean year-one snapshot of the deal, with no sign-up required.
No loan — P&I is $0
Quick examples:
Laundry, parking, pet or storage fees — not reduced by vacancy.
≈ $120.00/mo lost to vacancy
Dollar amounts below are entered per month; mortgage P&I is not an operating expense.
≈ $192.00/mo of gross rent
≈ $120.00/mo of gross rent
≈ $120.00/mo of gross rent
Deal Snapshot
Monthly Cash Flow
Cash-on-Cash Return
This property has negative cash flow at these numbers — it costs you $98.73 a month out of pocket.
Falls short of the 1% rule — rent is 0.80% of the price; you'd need $3,000.00/mo to hit 1%.
Investor Metrics
NOI (annual)
Cap Rate
DSCR
GRM
Effective Gross Income
Total Operating Expenses
Monthly Mortgage P&I
Total Cash Invested
Cash-Flow Waterfall (monthly)
From gross rent down to what lands in your pocket each month.
Where the Operating Dollar Goes
Annual Summary
Related Calculators
How This Calculator Works
This is a rental income statement built on the numbers you enter. It flows the money down in a fixed order: gross rent − vacancy + other income = effective gross income (EGI), then EGI − operating expenses = NOI, and finally NOI − mortgage payment (debt service) = cash flow. The mortgage is not an operating expense, which is exactly why NOI is calculated before it — that single distinction is what lets cap rate (financing-independent) and cash flow (financing-dependent) each tell you something different. Unlike the Mortgage Calculator (a homeowner's monthly payment), the Home Affordability Calculator (income → max price), or the business Cash Flow Calculator (a company's operating/free cash flow and DCF), this tool analyzes a single real-estate investment deal.
Effective Gross Income & NOI
EGI = rent x (1 − vacancy) + otherIncome
NOI = EGI − operatingExpenses
Vacancy reduces your rent only (other income is added afterward and isn't docked for vacancy). Subtracting all operating expenses — taxes, insurance, management, maintenance, capex reserve, HOA, utilities, and any other recurring costs — leaves net operating income, the income the property throws off before any loan.
Cash Flow & Debt Service (P&I)
P&I = loan x i(1+i)ⁿ / ((1+i)ⁿ − 1)
cashFlow = NOI − P&I (P&I = 0 if all-cash)
The mortgage payment uses the same standard amortization (PMT) engine as our mortgage and down payment tools, with the P&I = loan / n special case at a 0% rate and $0 P&I for an all-cash purchase. Subtract it from NOI and you have your cash flow — shown for both a month and a year, and shown plainly when it's negative.
Cap Rate, Cash-on-Cash & DSCR
capRate = NOI / purchasePrice x 100
cashOnCash = annualCashFlow / totalCashInvested x 100
DSCR = NOI / annualDebtService
Cap rate measures the unleveraged return on price and ignores your loan. Cash-on-cash divides annual cash flow by your total cash invested (down payment + closing costs + rehab), so it reflects leverage. DSCR is what lenders check — many want roughly 1.20–1.25 or higher.
GRM, the 1% Rule & the %↔$ Toggles
GRM = purchasePrice / grossAnnualRent
1% rule: monthlyRent ≥ 0.01 x purchasePrice
GRM and the 1% rule are fast screens you can run at a glance. Several fields — vacancy, property management, maintenance, capex reserve, and the down payment — can be entered as a percent of rent or a flat dollar amount, and a monthly/annual toggle lets you type expenses however you have them; everything is normalized internally so the metrics stay consistent.
Every figure comes from you and the math is deterministic — the same inputs always produce the same result. There are no live market rents, no maintained tax or insurance tables, and no appreciation forecast; the defaults are plain illustrative placeholders. For long-horizon, multi-year return math (appreciation, sale, and the like), pair this year-one snapshot with our IRR Calculator.
Tips for Analyzing a Rental Deal
Budget for Vacancy and Capex
The fastest way to fool yourself is to ignore vacancy and capital-expenditure reserves. A unit will sit empty between tenants, and roofs, HVAC, and water heaters eventually need replacing — both costs are real even in months you don't see them. Keep a realistic vacancy rate and a capex reserve in the inputs so your cash flow reflects how the property actually performs, not a best-case month. A deal that only works with zero vacancy and zero capex isn't really cash-flowing.
Use the 1% Rule as a Screen, Not a Verdict
The 1% rule (monthly rent ≥ 1% of price) is a handy first filter for sorting through listings quickly, but it's a gut check, not a decision. Plenty of properties that miss 1% still cash-flow well in low-tax, low-insurance markets, and some that clear it bleed money once real expenses are added. Use the rule to decide what's worth a closer look, then run the full cash-flow, cap-rate, and cash-on-cash numbers before you commit.
Know When to Use Cap Rate vs Cash-on-Cash
Cap rate ignores your financing, so it's the right tool for comparing different properties or markets on equal footing. Cash-on-cash includes your loan and your actual cash in, so it's the right tool for judging how hard your own money is working on a specific deal. Look at cap rate to ask "is this a good property?" and cash-on-cash to ask "is this a good deal for me at this price and this loan?"
Remember Financing Moves Cash Flow, Not Cap Rate
Because the mortgage is excluded from NOI, changing your down payment, rate, or term changes your monthly cash flow, cash-on-cash return, and DSCR — but it leaves the cap rate untouched. Putting more down lowers the payment and lifts cash flow but ties up more cash, often trimming cash-on-cash; a smaller down payment can boost cash-on-cash while shrinking your DSCR cushion. Toggle the down payment between percent and dollars and watch which metrics move to see this trade-off live.
Common Ways People Use a Rental Property Calculator
Screening a Listing Fast
Quick ScreenYou found a property online and want to know in seconds whether it is worth a deeper look. Enter the asking price, an estimated rent, a realistic vacancy rate, and your operating expenses to see the monthly cash flow, cap rate, and the 1% rule check immediately — then decide whether to spend more time on it or move on.
Comparing Two Deals Side by Side
Compare DealsChoosing between two rentals? Run each one, copy the shareable link or export a PDF, and compare the cap rate, cash-on-cash return, NOI, and DSCR head to head. Because cap rate strips out financing, it gives you an apples-to-apples read on the properties themselves, while cash-on-cash shows which one works harder for your specific cash and loan.
Deciding All-Cash vs Financed
FinancingToggle the all-cash switch on and off to see how leverage changes the picture. All-cash zeroes out the mortgage payment, so cash flow equals NOI and DSCR does not apply, but your total cash invested is the whole price — which usually lowers cash-on-cash. Financing reduces the cash in and can lift cash-on-cash while adding a debt-service payment and a DSCR to watch.
Setting a Target Rent or Offer Price
UnderwritingWork backward to a deal that pencils out. Adjust the rent until the property cash-flows where you want it, or lower the purchase price until the cap rate and cash-on-cash clear your targets. This turns the calculator into a negotiating and underwriting tool — you learn the rent you need to charge or the price you can afford to pay before the deal stops making sense.
What This Calculator Assumes
To keep results deterministic and evergreen, the analysis rests on a few clear assumptions:
- •A year-one snapshot: the tool models a single, steady-state year. There is no rent growth, no expense inflation, no property appreciation, no equity buildup over time, and no sale or multi-year projection — by design, so the answer stays honest and never needs updating. For long-horizon return math, use the IRR Calculator.
- •Your numbers, your call: every figure — price, rent, vacancy, and each operating expense — is the value you enter. Vacancy reduces rent only, percent-of-rent expenses are a share of gross scheduled rent, and defaults (a $300,000 price, 7% rate, 5% vacancy, and the like) are plain illustrative placeholders, not sourced market data or advice.
- •No taxes, depreciation, or 1031 effects: the calculator does not model income taxes, a depreciation schedule, the mortgage-interest deduction, or 1031 exchanges. Those depend on changing tax law; they are mentioned conceptually only, and the tool computes no tax benefit. Consult a tax professional for your situation.
- •Mortgage excluded from NOI; capex included: principal and interest is debt service, not an operating expense, so NOI is computed before it and cash flow after it. The capex reserve is treated as an operating expense here (as most rental calculators present it). Negative cash flow, cap rate, or cash-on-cash are valid outcomes and are shown clearly rather than hidden, and divide-by-zero cases (no loan, no cash invested, zero price) show a friendly message instead of an error.
Disclaimer: This tool provides estimates for educational and personal planning purposes and is not financial, tax, or investment advice. Actual returns depend on rents, vacancy, expenses, financing, and market conditions that can differ from your assumptions — verify rents, taxes, insurance, and financing with real quotes, and consult a qualified professional before buying an investment property.
Frequently Asked Questions
How do I calculate cash flow on a rental property?
Rental cash flow is what's left each month after every expense, including the mortgage. Start with your gross rent, subtract a vacancy allowance and add any other income to get your effective gross income, then subtract operating expenses (taxes, insurance, management, maintenance, capex reserve, HOA, utilities) to get net operating income (NOI). Finally subtract your mortgage principal-and-interest payment, and what remains is your monthly cash flow. This calculator does all of that automatically and shows the result for both a month and a full year.
What is NOI (net operating income)?
NOI is your property's income after operating expenses but before the mortgage payment, depreciation, and income taxes. You calculate it as effective gross income (rent minus vacancy, plus other income) minus all operating expenses. NOI is the backbone of real-estate analysis because it isolates how the property performs on its own, independent of how you financed it. Because the mortgage is excluded, two investors buying the same property with different loans will see the same NOI but different cash flow.
What is cap rate and what's a good one?
The capitalization rate is NOI divided by the purchase price, expressed as a percent — it tells you the unleveraged annual return the property's income produces. Because it ignores your financing, cap rate is a quick way to compare different properties or markets on an apples-to-apples basis. What counts as "good" varies widely by location and property type; many investors look for roughly 5%–10%, with higher cap rates often signaling higher risk or lower-growth areas and lower cap rates common in expensive, high-demand markets. Use it as a first-pass screen, not the whole decision.
What is cash-on-cash return and what's a good number?
Cash-on-cash return is your annual pre-tax cash flow divided by the actual cash you invested — your down payment plus closing costs plus any rehab. It answers "how hard is my own money working?" and, unlike cap rate, it accounts for leverage, so financing a deal can boost it. Many investors target something in the high single digits to low double digits (often cited around 8%+), but acceptable returns depend on your market and risk tolerance. If you bought all cash, your cash-on-cash return and your cap-rate-style return converge because there's no loan amplifying the result.
What is DSCR and why do lenders care?
The debt service coverage ratio is annual NOI divided by annual debt service (your mortgage principal and interest for the year). It measures whether the property's income comfortably covers the loan payments: a DSCR of 1.0 means income exactly equals the payment, while 1.25 means there's 25% more income than needed. Lenders that offer "DSCR loans" typically want at least 1.20–1.25 because it gives a cushion against vacancy or surprise expenses. If you pay all cash there's no debt service, so DSCR doesn't apply.
What is the 1% rule in real estate?
The 1% rule is a fast screening guideline that says a property's gross monthly rent should be at least 1% of its purchase price — for example, $2,000 a month on a $200,000 home. It's a back-of-the-envelope filter to decide whether a deal is worth a deeper look, not a guarantee of profit, and in many expensive markets few properties meet it. This calculator shows your rent-to-price ratio and whether the deal passes, alongside the real cash-flow and return metrics that matter more. Treat the 1% rule as a quick gut check, then rely on cash flow, cap rate, and cash-on-cash for the actual decision.
What is the gross rent multiplier (GRM)?
The gross rent multiplier is the purchase price divided by the property's gross annual rent — a simple ratio that tells you roughly how many years of gross rent equal the price. A lower GRM generally means a better value relative to the rent it produces, and it's handy for quickly comparing similar properties. Unlike cap rate, GRM ignores operating expenses and vacancy, so it's a rougher tool. Use it as a quick comparison alongside cap rate, not as a substitute for full cash-flow analysis.
How do vacancy and capex reserves affect my returns?
Vacancy is the income you lose when a unit sits empty or a tenant doesn't pay, and capital-expenditure (capex) reserves are money you set aside for big-ticket replacements like roofs, HVAC, and water heaters. Both are easy to forget and both can turn a "cash-flowing" deal negative once you include them realistically — which is why this calculator builds in a vacancy rate and a capex reserve by default. Skipping them makes a property look better on paper than it performs in real life. Entering honest vacancy and capex figures is one of the most important things you can do to avoid an unpleasant surprise.
Is negative cash flow always a bad thing?
Not necessarily, but it's something you should choose with open eyes. A property that loses money each month relies on appreciation, loan paydown, or tax benefits to come out ahead, and it requires you to feed it cash from your pocket — which can be risky if your income changes. Many experienced investors prioritize positive cash flow precisely because it makes a property self-sustaining through downturns. This calculator shows negative cash flow plainly rather than hiding it, so you can decide whether the trade-off is worth it for your strategy.
What expenses should I include, and is the mortgage one of them?
Operating expenses include property taxes, insurance, property management, maintenance and repairs, a capital-expenditure reserve, HOA dues, owner-paid utilities, and any other recurring costs of running the property. The mortgage payment is not an operating expense — it's debt service, which is why net operating income is calculated before it and cash flow after it. Keeping that distinction is what lets cap rate (which ignores financing) and cash flow (which includes it) each tell you something different. Closing costs and rehab aren't operating expenses either; they're upfront cash that counts toward your total cash invested for the cash-on-cash calculation.
Is a rental property a good investment?
A rental can be a strong investment when it produces reliable cash flow, sits in an area with steady demand, and fits your time horizon and risk tolerance — but "good" depends entirely on the numbers and your goals. Use this calculator to check that the deal cash-flows positively after realistic vacancy and capex, that the cap rate and cash-on-cash return clear your personal targets, and that the DSCR is healthy if you're financing it. Also weigh factors the math can't capture, like neighborhood trajectory, management effort, and liquidity. Run several scenarios (different rent, vacancy, and rate assumptions) before committing.
Does this calculator include taxes, depreciation, or appreciation?
No — by design it's a clean year-one snapshot of the operating deal, so it deliberately leaves out income taxes, depreciation, the mortgage-interest deduction, 1031 exchanges, and any multi-year appreciation or rent-growth forecast. Those depend on changing tax law and assumptions that would make the tool less reliable and require constant updates. What you get is the honest, evergreen core: cash flow, NOI, cap rate, cash-on-cash, DSCR, GRM, and the 1% rule on the numbers you enter. For long-term return projections, pair this with our IRR Calculator and consult a tax professional.