Free investment calculator
Enter the purchase price, rent and monthly costs — plus vacancy, management fees and closing costs. Nestlytics instantly shows your cash flow, gross yield and cash-on-cash return.
Start with the monthly rent, subtract the income you expect to lose to empty months (vacancy), then subtract every recurring cost: mortgage payment, maintenance, property management, and a monthly share of any yearly reserve. What remains is your monthly cash flow. Multiply it by 12 for annual cash flow. A positive number means the property pays for itself; a negative one means you top it up from your own pocket.
Gross rental yield is annual rent divided by the purchase price. There is no universal "good" number: it depends on the city, interest rates and how much the property is expected to grow in value. Cheaper areas often show higher yields but may carry more vacancy and repair risk, while expensive cities can have low yields but steadier tenants. Use yield to compare properties against each other, and look at cash flow to see whether a specific deal works for you.
Cash-on-cash return measures what your own money earns. It is annual cash flow divided by the total cash you put in up front — your down payment plus one-time closing costs. Unlike rental yield, it accounts for financing and expenses, so it is the clearer answer to "how hard is my invested cash working?"
Even good properties sit empty between tenants, during repairs or while you search for the right renter. A vacancy rate reserves part of the rent for those gaps: at 5%, you plan as if you collect 95% of the full-year rent. Because your mortgage and most costs continue while the unit is empty, a small change in vacancy can move cash flow noticeably — try raising it in the calculator to see how sensitive your deal is.
Include the mortgage payment, routine maintenance, property management fees (even if you self-manage, your time has value), and a reserve for larger surprises like a boiler or roof repair. Depending on where you live, also consider property taxes, insurance, building or HOA fees, utilities you pay, and letting or licensing fees. You can add these into the monthly maintenance figure so the results reflect your full costs.
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