Rental Property Calculator
Estimate a rental property's cash flow and returns before you buy, so you can compare its income with financing and operating costs.
- 2026 figures, checked October 26, 2026
- Private: runs in your browser
- How we check our work
Result
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Verify before you act: review these results with a licensed loan officer, real estate attorney or HUD-approved housing counselor before making any decision based on them.
Suggestions for your numbers
Updated as you type, from your inputs only. General information, not personal advice; confirm any change with a qualified professional.
See it over time
Hover over or tap the chart to see the numbers for any point.
What is a rental property calculator?
A rental property calculator estimates whether rent may cover a property's operating costs and mortgage payments. It can help you assess a potential purchase or review a property you already own. As an investment property calculator, it brings rent, vacancy, expenses and financing into one estimate.
The calculator reports cash flow, cash-on-cash return, cap rate and debt service coverage ratio (DSCR). Cash flow is the money left after operating expenses and mortgage payments. Cash-on-cash return compares annual cash flow with the cash you put into the purchase. Cap rate compares net operating income (NOI) with the property's price, before mortgage payments. DSCR compares NOI with the mortgage debt service. These measures answer different questions, so consider them together rather than relying on just one.
Why rental property returns matter
A property can bring in rent and still need cash from you each month. Cash flow helps show whether the rent you expect to collect can support the mortgage and the costs you entered. This can inform whether you proceed with a purchase, negotiate the price, change your financing plan or keep looking.
The other measures add context. Cap rate helps you compare a property's operating income with its price without letting different loan choices dominate the comparison. Cash-on-cash return focuses on the cash you tie up in the purchase. DSCR shows how much NOI is available in relation to mortgage payments. A lender may also consider its own criteria, which this calculator does not predict.
Treat the result as an estimate, not a promise. Actual rent, vacancy, repairs, insurance, taxes and financing can differ from your assumptions. This calculator is not individualized investment advice; consider reviewing the property and financing assumptions with a qualified real estate or tax professional.
How to use this rental property calculator
- Enter the purchase price, down payment, interest rate, loan term, closing costs and repairs at purchase. Use the loan terms you are considering, since a change in financing affects mortgage payments and the cash you invest.
- Enter monthly rent and an expected vacancy percentage. Vacancy reduces the rent counted as income, so avoid treating every scheduled rent payment as guaranteed.
- Add annual property taxes and insurance, plus monthly HOA costs if they apply. Enter property management, repairs and capital reserves as percentages of rent. These are operating cost assumptions, not mortgage costs.
- Review the cash flow and return measures. Check that the inputs reflect the property and loan you are evaluating. Try a different rent, price, down payment or cost estimate to see how the result changes.
Rental property calculator example
Worked example
Using the sample inputs—purchase price $350,000, down payment 25%, interest rate 7.25%, loan term 30 years, closing costs $8,000, repairs at purchase $5,000, monthly rent $2,700, vacancy 5%, property taxes per year $5,000, insurance per year $2,000, HOA per month $0, property management 8% of rent, repairs 5% of rent and capital reserves 5% of rent—the calculator estimates effective rent after vacancy of $30,780 and operating expenses of $12,540. That leaves NOI of $18,240. After annual mortgage payments of $21,489, annual cash flow is -$3,249, or monthly cash flow of -$270.75. With $100,500 cash invested, cash-on-cash return is -3.2%; cap rate is 5.2%; DSCR is 0.85x; and the rent-to-price result for the 1% rule is 0.77%. The negative cash flow means the entered rent does not cover the entered operating expenses and mortgage payments.
How to read rental property calculator results
Start with effective rent, operating expenses and NOI. Effective rent reflects the vacancy assumption. NOI is what remains after operating expenses, before mortgage payments. Cash flow then subtracts mortgage payments from NOI. If it is negative, plan for the shortfall rather than assuming rent alone will cover the property.
Cash-on-cash return relates annual cash flow to your cash invested, including the purchase cash and upfront costs entered. Cap rate sets NOI against the purchase price, so it does not show the effect of your loan terms. DSCR below 1.0x means NOI is less than the mortgage debt service in the estimate. The 1% rule is a quick rent-to-price screen, not a measure of expenses, financing or actual profit. Use the displayed result to prompt a closer review, not as a guarantee.
How to improve a rental property's numbers
- 01
Revisit the purchase price and financing
If the estimate shows a cash shortfall, consider negotiating the price or comparing loan offers. A larger down payment or a different loan term can change mortgage payments and cash-on-cash return, but also changes how much cash you commit. Compare the full set of results before deciding.
- 02
Check rent and vacancy assumptions
Support the rent estimate with current information about comparable rentals in the area. If you expect vacancies or concessions, include them instead of assuming every month is fully occupied. Better tenant screening and timely maintenance may help reduce avoidable turnover, but cannot remove vacancy risk.
- 03
Get specific about operating costs
Request current tax and insurance estimates, review HOA charges, and inspect the property's condition. Price likely repairs before making an offer. If you will manage the property yourself, consider the time involved as well as the management fee you entered.
- 04
Protect reserves and review actual results
Keep a cash reserve for repairs and periods without rent instead of treating all collected rent as spendable income. Once you own the property, compare actual income and expenses with your estimates and update the calculator when costs or financing change.
Common rental property calculator mistakes
Leaving out expenses
Taxes, insurance, HOA charges, management, repairs and capital reserves all affect the estimate. Check each line and use a realistic figure rather than leaving a cost blank just to improve the result.
Confusing NOI with cash flow
NOI is before mortgage payments. Cash flow subtracts them. A property can show positive NOI and still have negative cash flow when its debt service is high.
Treating estimates as guaranteed income
Rent, vacancy, repairs and other costs can change. Test less favorable assumptions too, and avoid making a purchase decision from a single optimistic scenario.
Using the 1% rule as a final decision
The rent-to-price screen does not include operating costs or financing. Use it as a quick comparison, then review cash flow, cap rate, cash-on-cash return and DSCR.
The rental property formula
NOI = effective rent - operating expenses. Cash flow = NOI - mortgage payments. Cash-on-cash = cash flow / cash invested.
Key terms
- Effective rent
- Rent after subtracting the vacancy allowance entered in the calculator.
- Net operating income (NOI)
- Effective rent minus operating expenses, before mortgage payments.
- Cash-on-cash return
- Annual cash flow compared with the cash invested in the property.
- Debt service coverage ratio (DSCR)
- NOI compared with mortgage debt service. A result below 1.0x means NOI is less than the debt service in the estimate.
Rental property questions
What is the 1% rule?
A quick screen: monthly rent at least 1% of the price.
What does a negative monthly cash flow mean?
It means the calculator's estimated operating income after expenses is less than the mortgage payment amount. You would need other funds to cover the projected shortfall, unless your actual income or costs differ from the inputs.
What is the difference between cap rate and cash-on-cash return?
Cap rate compares NOI with the property's price and does not include the effect of mortgage financing. Cash-on-cash return compares annual cash flow with the cash invested, so it reflects both financing and upfront cash costs.
Does the calculator include taxes on rental income?
It estimates property operating costs and cash flow from the inputs; it does not calculate income tax. Rental tax treatment depends on your circumstances, so ask a tax professional about your situation.
Can I use this for a property I already own?
Yes. Enter current rent, expenses and financing details to estimate its returns. Use actual figures where available, and consider updating the inputs when costs, rent or loan terms change.
Before you act on this result. Cordwell calculators and guides are educational estimates, not legal, tax, investment, lending or other professional advice. They rely on the numbers you enter and on simplified rules, and they can't see your full situation. Before you file, sign, borrow, invest, hire, change your withholding or form a business based on anything here, meet with a licensed loan officer, real estate attorney or HUD-approved housing counselor who can review your specific facts and confirm the numbers. Rules change, and official agency guidance always controls.