Rental Property Cash Flow and DSCR Calculator
Does a rental property actually pay? Enter the price, down payment, mortgage rate and amortization, rent and expenses, and this tool returns monthly and annual cash flow, cash-on-cash return, the debt service coverage ratio, and total return including principal paydown. The mortgage rate is a field you set, so nothing here goes stale. Nothing you enter is stored.
Last updated August 30, 2026
How it works
The tool builds the mortgage payment from the loan amount, your rate and the amortization, then works out net operating income from rent after vacancy and expenses. Cash flow is net operating income minus the annual mortgage payments. Cash-on-cash return divides annual cash flow by your down payment. The debt service coverage ratio, DSCR, divides net operating income by the mortgage payments, and lenders watch it closely. Total return adds the principal you pay down in the first year, which builds equity even when cash flow is thin.
A worked example
A $500,000 property with $100,000 down, a 6 percent mortgage over 30 years, $3,000 monthly rent, a 5 percent vacancy allowance and $8,000 of annual expenses. The mortgage runs about $2,398 a month. Net operating income is about $26,200, annual debt service about $28,800, so cash flow is slightly negative at about $2,600 a year. DSCR is about 0.91, below the 1.2 many lenders want. But roughly $4,900 of principal is paid down in year one, so total return on the down payment is still positive at about 2.3 percent. Change the rate and every number moves, which is the point of making it a field.
Why the rate is a field
Mortgage rates move, and a calculator with a rate baked in is wrong the moment rates change. Here the rate is yours to enter, so the tool stays correct whatever the market does. Run a few rates to see how sensitive the deal is; a property that only works at a low rate is a different investment from one that works across a range.
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Frequently asked questions
What is DSCR and why does it matter?
The debt service coverage ratio is net operating income divided by the mortgage payments. Above 1 the property covers its loan from rent; many lenders want 1.2 or more. It is one of the first numbers a lender checks.
What is cash-on-cash return?
Annual cash flow divided by the cash you put in, mainly the down payment. It measures the yield on your actual invested cash, separate from appreciation and principal paydown.
Why include principal paydown in total return?
Because each mortgage payment builds equity by reducing the loan. A property with thin cash flow can still build wealth through paydown, so total return gives a fuller picture than cash flow alone.
Is my data stored?
No. The calculation runs entirely in your browser. Nothing you enter is saved or sent anywhere.