Estimate cumulative return on initial down payment from fixed rent, operating costs, nominal mortgage payments and an entered end-of-hold sale scenario.
Profit equals sale value minus the remaining loan, plus holding-period cash flow, minus initial down payment. Return is this profit divided by the initial down payment; it is cumulative, not annualized. Later cash deficits are not added to the denominator. With no initial down payment, that return ratio is unavailable. Loan and holding periods use whole months, including immediate sale at a zero holding period.
Rent and operating costs remain fixed. Property tax and maintenance use purchase price; month-end mortgage payments use a fixed nominal annual interest rate and stop at payoff. Sale value uses entered appreciation, a scenario rather than a forecast. Transaction and financing fees, vacancy, rent or cost growth, PMI, income and capital-gains taxes and reinvestment are excluded. Numerically unresolved differences are unavailable rather than given a false profit sign.