How to calculate NOI.

Net operating income is the foundation of almost every rental metric: cap rate, DSCR and property value all start from it.

Updated September 26, 2026 · By Javier Castellanos Serrano, RentCaliber

The formula

NOI = gross rent − vacancy and credit loss + other income − operating expenses

Step by step

  1. Gross scheduled rent. What the property would earn if every unit were rented all year.
  2. Subtract vacancy and credit loss. Months empty between tenants and rent you fail to collect, often budgeted as a percentage of gross rent.
  3. Add other income. Parking, laundry, storage or pet fees.
  4. Subtract operating expenses. Property tax, insurance, maintenance and repairs, property management, HOA dues, utilities you pay, landscaping and similar recurring costs.

What NOI excludes

  • Mortgage principal and interest. NOI describes the property, not your financing.
  • Capital improvements such as a new roof, although many investors budget reserves for them separately.
  • Depreciation and income taxes, which depend on the owner.

A worked example

Gross rent ($2,800 × 12)$33,600
Vacancy (5%)−$1,680
Property tax−$4,500
Insurance−$1,800
Maintenance (5% of rent)−$1,680
Management (8% of collected rent)−$2,554
Net operating income$21,386

On a $300,000 purchase, that NOI gives a 7.13% cap rate. These are the example numbers in our rental property calculator, which does this math for you.

How NOI connects to other metrics

  • Cap rate = NOI ÷ price. See what is a good cap rate.
  • Value = NOI ÷ market cap rate, which is why raising NOI raises what a property is worth.
  • DSCR = NOI ÷ annual debt payments in our rental model; lenders often use a rent-based version instead. See DSCR loans explained.

Let the calculator build NOI for your property.

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General information for U.S. landlords, not legal, tax or insurance advice. Rules vary by state and city; confirm requirements with a local attorney, licensed agent or tax professional.