NOI vs Cash Flow
Net operating income (NOI) is a rental property's income after vacancy and operating expenses but before any mortgage payment, so it measures the property itself. Cash flow is what the owner keeps after also paying debt service and, usually, setting aside capital reserves. A property can have strong NOI and still produce little or negative cash flow if it is heavily financed.
NOI vs Cash flow side by side
| NOI | Cash flow | |
|---|---|---|
| Starts from | Gross rent and other income | NOI |
| Subtracts | Vacancy and operating expenses (tax, insurance, repairs, management, utilities you pay) | Debt service and capital reserves |
| Includes the mortgage? | No | Yes |
| Depends on who owns it? | No - the same for any owner | Yes - changes with each owner's loan |
| Used for | Cap rate, value, DSCR | Cash-on-cash return, personal budgeting |
| Includes income taxes or depreciation? | No | No (pre-tax cash flow) |
Full definitions: Net Operating Income, Cash Flow.
When each number matters
NOI is the number lenders and appraisers use. It drives the property's value through the cap rate and its borrowing capacity through the debt service coverage ratio, and it is the fairest way to compare two properties because it ignores how each is financed.
Cash flow is the number your bank account feels. It tells you whether the property pays you each month, needs topping up, or leaves enough cushion to survive a vacancy or a large repair.
Where the money goes between the two
The gap between NOI and cash flow is the cost of the loan plus the money you set aside for big-ticket replacements. Principal paid down is part of debt service, so it reduces cash flow even though it builds equity. Capital items such as a roof are not operating expenses; leaving out a reserve for them is the most common reason cash flow looks better on paper than in real life.
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.
Worked example
From NOI to cash flow on a $320,000 rental
Illustrative example - round numbers, not current market data. Calculated with Reaixo's calculator engines.
Assumptions
- Rent
- $2,800 a month
- Vacancy and credit loss
- 5%
- Operating expenses (tax, insurance, repairs, management)
- $9,600 a year
- Loan
- $240,000 (75% of $320,000) at 7.00%, 30 years
- Capital-expenditure reserve
- $2,400 a year
| Step | Calculation | Result |
|---|---|---|
| 1. Gross potential rent | $2,800 × 12 | $33,600 |
| 2. Net operating income | $33,600 − $1,680 vacancy − $9,600 expenses | $22,320 |
| 3. Annual debt service | $1,596.73 × 12 | $19,161 |
| 4. Cash flow before reserves | $22,320 − $19,161 | $3,159 |
| 5. Cash flow after reserves | $3,159 − $2,400 | $759 |
Annual cash flow after reserves: $759. The property produces $22,320 of NOI - a healthy-looking number - but after the mortgage and a realistic reserve the owner keeps $759 a year ($63 a month). NOI describes the property; cash flow describes this owner's deal.
What this calculation leaves out
- Pre-tax: income taxes and depreciation are not included.
- A different loan (more down, a lower rate, interest-only) changes cash flow but not NOI.
- Reserves are an estimate; some investors deduct them before NOI, others after. State which you use.
Common misconceptions
- The mortgage is an operating expense. It is not; it sits below NOI.
- Positive NOI means the property makes money for me. Only cash flow tells you that.
- Capital improvements belong in operating expenses. Replacements such as roofs and furnaces are capital items; budget them as a reserve.
- Cash flow is profit. It ignores appreciation, principal paydown, depreciation and income taxes.
Frequently asked questions
Is NOI the same as cash flow?
No. NOI is before the mortgage; cash flow is after the mortgage and usually after reserves, so cash flow is lower whenever there is a loan.
Does NOI include property taxes?
Yes. Property taxes and insurance are operating expenses and are subtracted before NOI.
Why do lenders use NOI instead of cash flow?
Because NOI shows how much income is available to pay any loan. Lenders divide NOI by the proposed debt service to see whether the property can carry it.
Calculators and guides
Recommended next step
Model rent, vacancy, every expense and the loan to see NOI and cash flow side by side.
Build a full income statement →Sources and review
No regulator defines these terms; the page follows common industry practice and labels rules of thumb as such.
Where this applies: Not regulated. Investment ratios are industry conventions; lenders and analysts may define the inputs differently, so always check how a figure was calculated.
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Worked examples use illustrative round numbers, not current market data. Rates, limits and program rules change - confirm current figures with your lender or a qualified professional.
General educational information, not financial, legal, tax or real estate advice. Rules vary by loan program, transaction and location - verify important decisions with qualified professionals.