Understanding Operating Expenses

What Counts as an Operating Expense

• Property taxes
• Insurance
• HOA dues
• Property management
• Maintenance and repairs
• Utilities paid by the owner
• Advertising and leasing costs
• Reserves for capital items

What Does Not Count

The mortgage payment is not an operating expense; it is debt service. Improvements that add value are not operating expenses; they are capital expenditures. Keeping these categories separate matters for NOI, cap rate, and tax treatment.

How They Drive the Metrics

Net operating income is gross income minus vacancy minus operating expenses. Lower operating expenses raise NOI, which raises cap rate. Since operating income and expenses are assumptions, small differences in assumptions produce very different results.

The Operating Expense Ratio

Owners sometimes compare operating expenses as a percentage of gross income, called the expense ratio. A lower ratio means more income reaches the bottom line, but the right level depends on property type, services included, and the market.

Model Them Honestly

The rental property calculator separates operating expenses from financing, so you can see their full effect on cash flow and cap rate. The investment property expenses guide lists the complete set, and the stress test shows what happens when expenses rise.