Rental Property Calculator

Evaluating a rental property relies on several interconnected financial formulas that measure profitability and risk. First, the loan amount is determined by subtracting your down payment from the purchase price: Loan Amount = Purchase Price - Down Payment. Monthly mortgage payments are computed using the amortization formula: Loan Payment = [Interest Rate * Loan Amount] / [1 - (1 + Interest Rate)^(-Loan Term)]. Gross operating income accounts for vacancy losses and management fees: Gross Income = Rent * (1 - Vacancy Rate) * (1 - Management Fee). Net Operating Income (NOI) subtracts monthly operating costs (such as property taxes, insurance, HOA fees, and maintenance) from the gross income. Finally, key investor metrics include the Capitalization Rate: Cap Rate = (NOI * 12) / Purchase Price, and Cash-on-Cash Return: Cash on Cash Return = (Cash Flow * 12) / Down Payment.

Imagine you are evaluating a single-family investment property with a purchase price of $300,000. You put down 20%, which equals $60,000, leaving a loan amount of $240,000 financed at an annual interest rate of 6% over a 30-year term. Your monthly loan payment comes out to approximately $1,438.93. The monthly rent is set at $2,500, with a 5% vacancy rate and an 8% property management fee, yielding a net monthly income before expenses of approximately $2,185. Factoring in $300 for property taxes, $100 for insurance, $150 for maintenance, and $50 for HOA fees, your total monthly operating costs equal $600. Subtracting the loan payment and operating costs from your adjusted gross income gives you a monthly cash flow of $146.07. Annually, this generates a cash-on-cash return of roughly 2.92% on your initial $60,000 investment, alongside a cap rate of about 6.34% based on your net operating income.

Always overestimate your vacancy rates and maintenance reserves to protect your cash flow against unexpected market downturns or major repairs. Keep in mind that location heavily influences property appreciation and insurance costs, so research local historical trends before locking in your inputs. Finally, double-check whether your HOA fees include amenities that might otherwise attract higher-quality tenants willing to pay a premium rental rate.