What Is Operating Expenses?
Operating expenses are the recurring costs of running a rental property - property taxes, insurance, repairs and maintenance, management fees, owner-paid utilities and similar costs. They are subtracted from rental income to calculate net operating income and never include mortgage payments, depreciation or capital improvements.
Operating Expenses in plain English
Operating expenses are what it costs to run a rental day to day: property taxes, insurance, repairs and maintenance, property management, utilities the owner pays, HOA dues, landscaping, licensing and similar costs.
They are subtracted from rental income to find net operating income. Mortgage payments, depreciation and capital improvements are not operating expenses.
Worked example
Why a $2,400-a-month rental loses money
Illustrative example - round numbers, not current market data. Calculated with Reaixo's calculator engines.
Assumptions
- Rent
- $2,400 a month
- Vacancy
- 6%
- Tax and insurance
- $5,400 and $1,800 a year
- Repairs, management, capital reserve
- 8% of rent, 9% of collected rent, 5% of rent
- Loan
- $240,000 at 7.25%, 30 years
| Step | Calculation | Result |
|---|---|---|
| 1. Effective gross income | $28,800 − $1,728 vacancy | $27,072 |
| 2. Operating expenses | $5,400 + $1,800 + $2,304 + $2,436 | $11,940 |
| 3. Net operating income | $27,072 − $11,940 | $15,132 |
| 4. Debt service | $240,000 at 7.25% | $19,647 |
| 5. Cash flow after capital reserve | $15,132 − $19,647 − $1,440 | −$5,955 |
Annual cash flow: −$5,955. The rent covers operating costs comfortably (NOI is $15,132), so the property is not the problem - the financing is. Debt service of $19,647 is more than the NOI, leaving −$5,955 a year (−$496 a month) after reserves.
What this calculation leaves out
- Expense ratios are illustrative; use the actual tax bill, an insurance quote and your own repair history.
- A negative cash flow can still be a deliberate choice for appreciation or paydown - but it needs cash reserves to sustain.
Try it: Operating Expenses with your own numbers
Interactive and illustrative: change any value and the results update instantly in your browser. The figures come from the same engines as REAIXO's full calculators.
From rent to cash flow: the NOI waterfall
Gross rent shrinks at every step: vacancy, operating expenses, the mortgage and reserves. NOI is the property's income before financing; cash flow is what you keep.
- Net operating income
- $23,454
- Per year, before the mortgage
- Estimated cash flow
- $3,064
- $255 a month
- Cap rate on the price
- 7.33%
Show the numbers as a table
| Step | Per year | Per month |
|---|---|---|
| Gross scheduled income | $36,000 | $3,000 |
| Vacancy and credit loss | −$1,800 | −$150 |
| Effective gross income | $34,200 | $2,850 |
| Operating expenses | −$10,746 | −$896 |
| Net operating income | $23,454 | $1,955 |
| Debt service (principal and interest) | −$18,680 | −$1,557 |
| Capital-expenditure reserve | −$1,710 | −$143 |
| Estimated cash flow | $3,064 | $255 |
Formula
Effective gross income = Gross scheduled income − VacancyNOI = Effective gross income − Operating expensesCash flow = NOI − Debt service − Capital-expenditure reserveAssumptions
- 30-year fixed loan, no points; one unit with no other income, HOA or utilities.
- Vacancy is taken off gross rent; management, maintenance and the capital-expenditure reserve are a share of collected rent.
- The capital-expenditure reserve sits below NOI: it is cash set aside, not an operating expense.
- Income taxes, depreciation and appreciation are left out.
Why it matters
Underestimating operating expenses is the most common reason a rental underperforms. Taxes and insurance can rise after purchase, and repairs scale with the age of the building.
Common mistakes
- Leaving out management because you plan to self-manage.
- Using the seller's tax bill when the sale may trigger a reassessment.
- Mixing capital replacements into operating expenses.
Compare and common questions
Operating Expenses: frequently asked questions
What is included in operating expenses for a rental?
Property taxes, insurance, repairs and maintenance, management, owner-paid utilities, HOA dues and other recurring costs of running the property.
Are mortgage payments operating expenses?
No. Debt service is subtracted after net operating income, so the property can be evaluated independently of its financing.
What is an operating expense ratio?
It is operating expenses divided by effective gross income. It helps compare how expensive properties are to run, but varies widely by property type and age.
Related Terms
Where it fits
- Investing, Leasing & Operations: before this, Vacancy Rate; next, Property Management Fee.
More Investing Terms
Recommended next step
List every expense line and see its effect on NOI.
Rental cash flow calculator →Sources and review
- Publication 527, Residential Rental Property, Internal Revenue Service. Supports: Rental expenses such as taxes, insurance, repairs and management, and the separate treatment of improvements.
Where this applies: Not regulated. Investment ratios and budgeting conventions are industry practice; lenders and analysts may define inputs differently.
Last reviewed: · Updated:
Examples use illustrative figures; rules of thumb are labelled as such. Rates, limits and program rules change - confirm current figures with your lender or a qualified professional.
This definition is provided for general educational purposes and is not financial, legal, tax, or real estate advice. Verify important decisions with appropriately qualified professionals.
Apply these investment calculations to a real property
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