Most rental property calculators answer one question: what does this property return at this price? This rental property calculator answers that, and then the question an investor asks next: what is the most I can pay and still hit my target? It shows monthly cash flow, cap rate, cash-on-cash return and debt coverage, then works backward to the highest price that meets your target and the rent you need to break even.
If you are an agent, it is also a quick way to run the numbers with an investor client before you write an offer. The figures already in the boxes are an example property, not a recommendation.
Rental property calculator
Change any number. Results update as you type.
Estimates only, not financial or tax advice. The highest-price figures keep rent, rate, expenses and property tax unchanged.
Prefer a spreadsheet? Download the free Excel version. It uses the same formulas, opens in Google Sheets too, and has a note next to every input explaining what it means.
About this tool: free to use, with no sign-up and no payment. Built and maintained by jp, who runs Realty AI Desk. The formulas were last checked in October 2026. If you spot an error, tell us through the contact page.
What each number means
- Net operating income (NOI). Rent and other income, minus vacancy and every operating expense. It does not include the mortgage.
- Cash flow. NOI minus the loan payments. This is what the property puts in, or takes out of, your pocket.
- Cap rate. NOI divided by the price. It compares properties as if they were bought with cash, which is why it ignores the loan.
- Cash-on-cash return. Yearly cash flow divided by the cash you put in: down payment, closing costs and upfront repairs.
- Debt service coverage ratio (DSCR). NOI divided by the yearly loan payments. Below 1.0, the rent does not cover the mortgage after expenses. Lenders set their own minimums for investment loans.
- Gross rent multiplier. Price divided by gross yearly income. A lower number means you pay less per dollar of rent.
- The 1% rule. Monthly rent as a percentage of the price. It is a quick screen used by many investors, not a standard, and it says nothing about expenses.
The worked example
The example is a $300,000 property bought with 25% down at a 7% rate on a 30-year loan, with closing costs of 3% and $5,000 of repairs before the first tenant. It rents for $2,400 a month.
- The loan is $225,000, and principal and interest come to $1,496.93 a month.
- Cash invested is $89,000: $75,000 down, $9,000 in closing costs and $5,000 in repairs.
- Gross scheduled income is $28,800 a year. After 5% vacancy, 8% management, 5% maintenance, a 5% capital reserve, $3,600 of property tax and $1,500 of insurance, NOI is $17,191.20.
- Loan payments are $17,963.17 a year, so the property loses $771.97 a year, or $64.33 a month.
The ratios tell the same story from different angles. The cap rate is 5.73%, the cash-on-cash return is minus 0.87%, the DSCR is 0.96 and rent is 0.80% of the price, which fails the 1% screen.
The reverse view: how much can you pay?
A negative cash flow does not always mean walk away. It may mean the price is wrong for the rent. The bottom panel answers that directly, keeping the rent, the rate and the expenses as they are.
- Highest price for an 8% cash-on-cash return: $204,081. At that price the down payment, closing costs and loan all shrink, and the same rent produces an 8% return on the cash invested.
- Highest price for a 6% cap rate: $286,520. This is NOI divided by 6%, and it ignores financing.
- Break-even rent: $2,483.11 a month. At that rent, cash flow is zero at the full $300,000 price.
Those three numbers turn a vague “it doesn’t work” into something you can negotiate with. The gap between $300,000 and $204,081 is the size of the problem on price, and the gap between $2,400 and $2,483 is the size of it on rent.
The formula behind the highest price is simple enough to check by hand. Yearly loan payments, down payment and closing costs all rise in line with the price, while NOI does not, so the calculator solves for the price at which cash flow divided by cash invested equals your target. Because it holds property tax constant, recheck the tax bill at the price you land on.
The assumptions that move the answer most
- The interest rate. In the example the loan payment is the largest single cost. Run the calculator at your quoted rate, not the rate you hope for.
- Rent. Use rents from comparable leased properties, not the asking rent on a listing.
- Property tax. The seller’s current bill may not be what you pay. Ask the county how the property will be assessed after the sale.
- Capital expenditures. Roofs, water heaters and HVAC systems wear out on their own schedule. A reserve that looks pessimistic on paper is what keeps the first big repair from wiping out a year of cash flow.
- Vacancy and management. Self-managing does not make management free. It moves the cost to your time.
How the calculator treats each expense
Vacancy, maintenance and the capital reserve are calculated as a percentage of gross scheduled income, meaning rent plus any other income as if the unit were always occupied. Management is a percentage of the income collected, because management fees are typically charged on rent received; check the agreement. Taxes, insurance, HOA dues and owner-paid utilities are fixed amounts. If you use different conventions, adjust the percentages to match.
The calculator does not include appreciation, principal paydown or tax effects such as depreciation. Those can matter a great deal to an investor, but they depend on assumptions about the future and on the investor’s tax situation, which is why they are left out of a cash-flow screen.
Rental property calculator FAQ
What is a good cash-on-cash return?
There is no single answer. It depends on the market, the risk of the property and what else the investor could do with the cash. That is why the calculator asks for your target instead of assuming one.
What is the difference between cap rate and cash-on-cash return?
Cap rate ignores the loan and compares the property’s income with its price. Cash-on-cash includes the loan and compares cash flow with the money you put in. The same property can have a decent cap rate and a negative cash-on-cash return when borrowing is expensive, as the example shows.
Does the 1% rule still work?
It works as a first filter to decide which listings deserve a full analysis. It does not replace one, because it ignores taxes, insurance, the interest rate and every other expense.
Can I use this for a multifamily property?
Yes, for a small one. Enter the total monthly rent for all units and the property’s total expenses. Larger buildings usually need a unit-by-unit rent roll, which this calculator does not model.
For pricing the property itself, see what AI can and cannot do in a CMA. For the commission side of the same deal, use the real estate commission calculator.
Estimates only. This calculator is not financial, tax or investment advice.