Rental Property Cash Flow Calculator
Work out the monthly and annual cash flow of a rental property from rent, vacancy, operating costs and the mortgage — plus NOI, cap rate, cash-on-cash return, DSCR, break-even rent and occupancy, a year-by-year projection with rent and expense growth, equity, sale proceeds, total profit and IRR.
How it works
Collected income = (rent + other income) × (1 − vacancy%) · OPEX = tax + insurance + maintenance + collected × mgmt% + rent × CapEx% + other · NOI = collected − OPEX · Cash flow = NOI − mortgage (P&I) · Cap rate = annual NOI ÷ price · Cash-on-cash = annual cash flow ÷ (down payment + closing + repairs) · DSCR = NOI ÷ mortgage · IRR: the rate r where −cash invested + Σ cash flowₜ ÷ (1 + r)ᵗ + net sale ÷ (1 + r)ᴴ = 0
Cash flow is what actually lands in your pocket after the tenant pays and every bill is settled. It starts from collected income — gross rent plus any parking or laundry income, minus a vacancy allowance — then subtracts operating expenses (property tax, insurance, maintenance, management, an optional capital-expenditure reserve and other costs) and finally the mortgage principal and interest. Net operating income (NOI) excludes the mortgage because it measures the property itself; cash flow subtracts financing on top, so a property can show a healthy NOI yet negative cash flow simply because it is heavily leveraged. You can type your mortgage payment, have it calculated from the price, down payment, rate and term, or model an all-cash purchase. With a purchase price the calculator adds the return measures investors compare: cap rate (NOI ÷ price), cash-on-cash return (cash flow ÷ the cash you put in), debt service coverage, gross rent multiplier and the 1% rule. Break-even rent and break-even occupancy show how much room you have before the property stops paying for itself, and a sensitivity table shows cash flow at rents 5–10% higher or lower and different vacancy rates. Under More options, rent growth, expense growth, appreciation, a holding period and selling costs drive a year-by-year projection of cash flow, loan balance and equity, ending with the net sale proceeds, total profit, equity multiple and internal rate of return (IRR).
Worked example
On $2,200 rent with a 5% vacancy allowance you collect $2,090. Operating expenses are $250 tax + $100 insurance + $150 maintenance + 8% management ($167.20) + $60 other = $727.20, leaving $1,362.80 NOI. Subtract a $1,300 mortgage payment and monthly cash flow is $62.80, or $753.60 a year. On a $250,000 purchase that is a 6.54% cap rate; with 20% down ($50,000) and $7,500 of closing costs, the $57,500 invested earns a 1.31% cash-on-cash return, and the DSCR is 1,362.80 ÷ 1,300 = 1.05. Holding 10 years with 3% rent, expense and price growth and selling for 6% costs, the projection shows how equity, not cash flow, drives most of the return.
Frequently asked questions
Why subtract a vacancy allowance if the unit is occupied?
Even a good rental sits empty between tenants and occasionally has a non-paying month. Budgeting 5–8% of rent for vacancy keeps your projection honest across the years you actually hold the property, rather than assuming 100% occupancy forever.
What is the difference between cash flow and NOI?
Net operating income is collected rent minus operating expenses only — it ignores how you financed the purchase. Cash flow takes NOI and subtracts the mortgage payment, so two investors buying the same building can have very different cash flow depending on their loan.
Should the mortgage payment include taxes and insurance?
Enter only principal and interest, because this calculator already counts property tax and insurance as separate operating expenses. If your loan escrows taxes and insurance, exclude those portions from the payment, or choose “Calculate it” and let the calculator work out principal and interest from the loan.
What is a good cash flow, cap rate or cash-on-cash return?
There is no single target, but many investors look for at least $100–$200 a month of cash flow per door after reserves, a cash-on-cash return of 8–12%, and a DSCR of 1.25 or more. Cap rates depend heavily on the market: 4–5% is common in expensive cities, 7–10% in cheaper areas with more risk.
What is a CapEx reserve and why add one?
Capital expenditures are the big, infrequent replacements — roof, furnace, water heater, flooring, appliances. They are not monthly bills, so they are easy to forget, but they arrive eventually. Setting aside 5–10% of rent each month spreads that cost and gives a more realistic cash flow.
What do break-even rent and break-even occupancy mean?
Break-even rent is the monthly rent at which cash flow is exactly zero with your vacancy and expenses. Break-even occupancy is the share of the year the property must be rented to cover operating costs and the mortgage. Lenders and investors like break-even occupancy below about 85%.
How is IRR different from cash-on-cash return?
Cash-on-cash looks only at the first year’s cash flow against the cash you invested. IRR takes every year’s cash flow plus the net proceeds when you sell, and finds the single annual return that makes them worth exactly what you put in — so it captures appreciation and loan pay-down as well as rent.
Related calculators
Educational estimate, not financial or investment advice. Real returns depend on financing, local costs and market conditions.