Net Operating Income Calculator - Property NOI Estimate

A net operating income (NOI) calculator estimates the income a property or operating business produces after recurring operating expenses but before financing costs and income taxes. Enter gross operating income along with property management, maintenance, insurance, property taxes, owner-paid utilities, and other operating expenses. The calculator reports NOI, total operating expenses, the expense ratio, and NOI margin. It is particularly useful for rental-property underwriting, commercial real-estate comparisons, budgeting, and evaluating how a change in costs affects property-level profitability. The core formula is NOI = gross operating income − operating expenses. Operating expenses are the sum of all six expense categories in the form. Expense ratio equals operating expenses ÷ gross operating income, while NOI margin equals NOI ÷ gross operating income. Both ratios are expressed as percentages whenever gross income is positive. The calculation treats all entered amounts as belonging to the same period, such as one month or one year. A negative NOI is allowed because it can accurately signal that recurring operating costs exceed income. NOI deliberately excludes mortgage principal and interest, income tax, depreciation, capital expenditures, and acquisition costs. Those items matter for investor cash flow and after-tax returns, but including them would turn NOI into a different measure. Gross operating income should reflect collectible rent and other operating revenue after vacancy or credit loss if that is how you prepare your underwriting. Be consistent about whether utilities, common-area maintenance, and management fees are paid by the owner or recovered from tenants. Use this calculator to compare scenarios such as higher occupancy, a management-fee change, or a maintenance reserve. Then pair NOI with purchase price to evaluate capitalization rate, or with debt service to evaluate coverage, using compatible annual figures. Actual property performance can be affected by lease terms, seasonal costs, repairs, rent escalation, and nonrecurring events. Check operating statements and lease documents before making a purchase, lending, or management decision.