Underwrite a rental in seconds — cash flow, cap rate, cash-on-cash, and ROI all in one view.
A free, no-signup rental property underwriter. Plug in price, financing, rent, and operating expenses to see whether a deal cash-flows — and what your actual return on cash invested looks like.
Direct answers to the most common questions, in plain language. Skim if you're in a hurry; dig deeper below.
8–12% is solid in 2026 markets.
Most U.S. investors target 8–12% cash-on-cash on long-term rentals after all expenses including vacancy and management. Below 6% is hard to justify when Treasuries pay similar yields. Above 15% usually means you missed an expense.
Monthly rent minus every monthly cost, including P&I.
Cash flow = monthly rent + other income − (mortgage P&I + property tax + insurance + HOA + management + maintenance reserve + vacancy reserve). The calculator above runs this every keystroke.
Monthly rent should be at least 1% of price.
A $250,000 house should rent for $2,500/month to clear the 1% rule. It is a quick screen, not a verdict — high-appreciation markets routinely break it. Use it to filter, then underwrite the survivors with this calculator.
Yes, but treat cash flow as the floor.
Total ROI in year one combines cash flow, principal paydown, and appreciation. Cash flow and paydown are mostly real. Appreciation is a forecast — be conservative (2–3%) and never depend on it to make a deal work.
The mechanics in short answers — no jargon, no upsell.
Net Operating Income equals gross rent minus every operating expense — but NOT the mortgage. NOI tells you whether the asset itself is productive.
Cap rate = NOI ÷ purchase price. It is finance-agnostic. Two investors paying cash at the same price get the same cap rate, regardless of their tax situation.
Cash-on-cash = annual cash flow ÷ cash invested (down payment + closing). It tells you what your actual money is earning, after leverage.
Cash flow is the visible piece. Principal paydown and appreciation are silent — they add to ROI without ever hitting your bank account in year one.
Designed so anyone can model their situation in under a minute, with or without a finance background.
Cap rate, cash-on-cash, monthly cash flow, and total ROI all update in real time as you type.
Property management, vacancy, and maintenance reserves are included by default — the costs new investors miss.
Two metrics tell different stories. We surface both cap rate and cash-on-cash so you can choose the right lens.
Watch cumulative cash flow and equity build year by year with rent growth and appreciation assumptions.
Adjust vacancy and maintenance to see how a soft year turns a winner into a break-even.
Negative cash flow shows up red, immediately. No need to build the spreadsheet to know the answer.
Everything you might ask before, during, or after using this tool.
Cap rate measures the property's return independent of financing: NOI divided by purchase price. Cash-on-cash measures YOUR return on the cash you put in: annual cash flow divided by down payment + closing. Cap rate is the asset; cash-on-cash is the deal.
Vacancy (assume 5–8% even in hot markets), property management (8–10% even if you self-manage today — your time has value), maintenance reserves (5–10% of rent), capital expenditures (roof, HVAC, hot water), and turnover costs between tenants. Skipping these makes every deal look great on paper.
Less than it used to be. The 1% rule (monthly rent ≥ 1% of price) worked when interest rates were 4%. With rates near 7%, you often need closer to 1.1–1.2% for cash flow to clear. Use it as a fast filter, not a green light.
A common target is $150–$300 per door per month, AFTER all expenses and reserves. Less than $100/door leaves no margin for a bad year. More than $400/door is usually possible only in lower-cost markets.
Yes, even if you self-manage. Plug in 8–10% management. If you ever scale, refinance, or want to sell, the next owner will pay it — and your numbers should reflect a transferable, reproducible business.
Be conservative: 2–3% per year is the long-run U.S. average. Some markets do 5–7%, but planning around that is forecasting. Use 2–3% in underwriting and treat anything more as a bonus.
No — it shows pre-tax cash flow and ROI. Depreciation typically shelters most of your cash flow from income tax in early years, so your after-tax return is usually better than this calculator shows. Talk to a CPA for your specific situation.
A back-of-envelope shortcut: assume operating expenses (excluding the mortgage) eat about 50% of gross rent. If you have not built a detailed budget, this gets you a rough cap rate fast. Use the detailed calculator above when you actually offer.
Other Lazysmirk tools that pair well with this one.
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Find out how much house you can afford. Enter income, debts, down payment, and rate to get your max home price, recommended budget, monthly PITI, and the binding constraint.
Compare the true financial outcome of buying a home vs renting and investing the difference, year by year, with a break-even chart and clear recommendation.
Estimate your total US mortgage closing costs — lender fees, title, government taxes, and prepaids — and find out exactly how much cash you need to close.
Rules of thumb survive because they are fast. The 1% rule says monthly rent should be at least 1% of purchase price — a $250k house renting for $2,500/month. The 50% rule says operating expenses will swallow about half of gross rent, before the mortgage. Together, they let you sift a hundred listings in a coffee break.
They are not verdicts. High-appreciation markets routinely violate the 1% rule and still print money over a decade. Class-A new construction often beats the 50% rule because there is nothing to fix. Use the rules to decide which deals deserve a real underwriting pass — that is what the calculator above is for.
Both, and they answer different questions. Cap rate values the property in a vacuum, ignoring how you paid for it. Cash-on-cash measures what your specific dollars earn given your specific financing. Two investors buying the same building can have identical cap rates and wildly different cash-on-cash because one paid cash and the other put 25% down.
When comparing properties: use cap rate. When comparing your money's alternatives (stocks, bonds, another rental): use cash-on-cash. Healthy 2026 numbers are roughly 6–8% cap and 8–12% cash-on-cash on long-term rentals, but the right benchmark depends on your market and asset class.
Two short notes worth reading before you trust any number on this page.
Your loan amount, rate, and prepayment inputs never leave your device. No accounts, no cookies on your numbers, no analytics on the values you type. Disconnect from the internet and it still works.
We are not a bank, NBFC, advisor, broker, or distributor of any financial product. The numbers shown here are estimates for educational purposes only, based on the inputs you provide.
Results are not financial, legal, or tax advice. Please consult a qualified professional before any decision about your loan, investments, or personal finances. Actual loan terms and charges depend on your bank and individual circumstances.
