Does NOI include mortgage payments or other debt service?

No. By definition, NOI is calculated before any financing costs. Principal and interest payments on loans belong in debt service and are handled in DSCR or cash‑on‑cash return calculations, not in NOI.

Should I include capital expenditure (CapEx) reserves in operating expenses?

Many lenders and conservative investors do include a CapEx reserve line (for roofs, HVAC replacements, parking lot resurfacing, etc.) when underwriting NOI. If you want a more conservative figure, add a reasonable annual reserve amount to operating expenses before running the calculation.

Can I use monthly numbers instead of annual?

This calculator expects annual figures. If you only have monthly rent and expense data, multiply each item by 12 first so that gross income, vacancy, and expenses are all on the same annual basis before computing NOI.

Does NOI include property taxes, insurance, and utilities?

Yes. Property taxes, insurance, and any utilities you pay on behalf of the property are core components of operating expenses. The key is to separate them from debt service and owner‑specific costs like income taxes.

How is NOI different from EBITDA?

NOI is a real‑estate‑specific metric focused on property‑level income and expenses before financing and income taxes. EBITDA (earnings before interest, taxes, depreciation, and amortization) is a broader business metric that can include corporate‑level overhead and is not tied to a single property’s operating statement.

What NOI do lenders and appraisers look at?

Most lenders and appraisers prefer a stabilized NOI based on trailing financials adjusted for normal vacancy and a realistic expense load. They may also apply their own vacancy and expense assumptions regardless of the numbers you provide, which is why it is helpful to understand and model NOI the way they do.

finance calculator

Net Operating Income (NOI) Calculator

Compute NOI by subtracting vacancy and operating expenses from gross income for clear property underwriting.

Results

Vacancy cost: $6,000
Effective gross income: $114,000
Net operating income: $79,000
Expense ratio: 29.17%

Overview

Net operating income (NOI) sits at the center of almost every rental and commercial real estate underwriting model. Lenders use it to test debt service coverage, investors use it to back into cap rates and values, and brokers lean on it when creating offering memoranda. This NOI calculator gives you a clean, consistent way to move from gross income to NOI by explicitly backing out vacancy and operating expenses, so you can compare deals on the same footing instead of trusting opaque broker pro formas.

How to use this calculator

Collect or estimate the property’s annual gross rental and other recurring income. For multifamily, this usually means in‑place rent roll plus consistent ancillary fees; for commercial, include base rent plus recurring CAM reimbursements where appropriate.
Choose a vacancy allowance that reflects market conditions and lender expectations. Many underwriters use at least 5%–8% even if current occupancy is higher, especially when pro formas assume rent growth.
Enter annual operating expenses, making sure to include taxes, insurance, maintenance, management, and utilities you pay on behalf of tenants. Add reasonable reserves or replacement allowances if you want a conservative NOI.
Review the calculated vacancy cost and effective gross income to confirm they look sensible relative to your market and rent roll.
Look at the resulting NOI and expense ratio. Compare these outputs to similar properties, lender underwriting standards, or rules of thumb you use for that asset class and location.
Export or copy the NOI into your cap rate, DSCR, and cash‑on‑cash return calculators so you can move from income to value, financing capacity, and investor returns without re‑entering numbers in multiple places.

Inputs explained

Gross rental income: Annual scheduled rent plus other recurring income before any deductions. Use actual in‑place numbers if you have them, or carefully documented pro forma rents if you are underwriting future stabilized income. Include consistent ancillary income like parking, storage, and pet fees but avoid one‑time charges.
Vacancy allowance (%): The percentage of gross income you expect to lose to physical vacancy, turnover downtime, non‑payment, and related credit issues. Even properties that are currently full should be underwritten with some vacancy allowance to reflect long‑term reality and lender stress tests.
Operating expenses: All recurring property‑level costs required to keep the building running and generating income: property taxes, insurance, repairs and maintenance, property management, common utilities, landscaping, snow removal, HOA dues, compliance inspections, and similar items. Exclude mortgage payments, income taxes, and major capital expenditures such as full roof replacements or system upgrades.

Outputs explained

Vacancy cost: The dollar amount of income you expect to lose to vacancy and credit loss, calculated as Gross income × Vacancy %. This makes it clear how aggressive or conservative your vacancy assumption is in actual dollars, not just as a percentage.
Effective gross income: Gross income minus vacancy cost. This is the income you expect to actually collect before operating expenses and is the base many lenders use when applying expense ratios and DSCR tests.
Net operating income: Effective gross income minus operating expenses. NOI is the core measure of property‑level profitability before debt service and income taxes, and it is the numerator in basic cap rate calculations (NOI ÷ Value).
Expense ratio: Operating expenses divided by effective gross income, expressed as a percentage. It shows what share of collectible income is consumed by expenses, which helps you benchmark a deal against similar properties or rules of thumb (for example, 35%–45% expense ratios on many stabilized multifamily assets).

How it works

You start by entering gross rental income, which represents the total scheduled rent and recurring ancillary income (parking, storage, pet fees, RUBS allocations, etc.) before accounting for vacancy or any expenses. This is sometimes called potential gross income when all units are assumed to be fully occupied and paying at the current rent roll.

Next, you choose a vacancy allowance percentage. Rather than plugging in a specific number of vacant units, the calculator applies a simple vacancy factor to gross income: Vacancy cost = Gross income × Vacancy %. This step forces you to think about economic vacancy and credit loss, not just physical vacancy.

Effective gross income (EGI) is then computed as Gross income minus Vacancy cost. EGI represents the income you reasonably expect to collect after typical downtime and non‑paying tenants, and is the starting point for many lenders’ cash flow analyses.

You then enter your annual operating expenses. These should include ongoing items like property taxes, insurance, repairs and maintenance, property management fees, common area utilities you pay, trash, lawn/snow, HOA dues, and other recurring operating costs. Crucially, they should exclude debt service (principal and interest), income taxes, and one‑time capital expenditures.

The calculator derives NOI using the standard definition: NOI = Effective gross income − Operating expenses. Because debt service and income taxes are not included, NOI is an unlevered figure that is comparable across different capital structures and useful for valuing properties via cap rate.

Finally, the tool computes an expense ratio, which is Operating expenses divided by Effective gross income. This ratio gives you a quick sense of whether expenses look lean or heavy relative to income, and makes it easier to spot unrealistic pro formas where expenses are understated just to make the deal look better.

By keeping the math this transparent—gross income, less vacancy, less operating expenses—the calculator gives you a repeatable framework you can use across single‑family rentals, small multifamily, larger apartment buildings, or basic commercial properties where the income and expense model follows the same structure.

Formula

Vacancy cost = Gross income × Vacancy %
Effective gross income = Gross income − Vacancy cost
NOI = Effective gross income − Operating expenses
Expense ratio = Operating expenses ÷ Effective gross income

When to use it

Running quick NOI pulls on a stack of listings so you can filter down to only the properties that clear basic income and expense hurdles before doing deeper analysis.
Testing how changes in vacancy assumptions or expense tightening impact NOI, cap rate, and DSCR for a deal you are trying to make work.
Normalizing broker pro formas, which often use optimistic vacancy or light expense assumptions, into your own underwriting standards for a more conservative view.
Benchmarking existing holdings by recalculating NOI from recent trailing‑12 (T‑12) financials and comparing expense ratios to what you see in new acquisitions.
Supporting lender conversations by quickly showing how your NOI and expense assumptions line up with their underwriting guidelines and stress‑test scenarios.

Tips & cautions

When in doubt, lean conservative on both vacancy and expenses. Deals rarely fall apart because you slightly underestimated NOI; they more often disappoint when income is lower or expenses are higher than rosy pro formas suggested.
Always reconcile the calculator’s operating expenses with a T‑12 and a forward‑looking budget. If the numbers are materially different, understand why before relying on the NOI for offers or financing decisions.
Keep debt service and income taxes out of operating expenses. Use this NOI as the starting point for separate DSCR and cash‑on‑cash return calculations rather than mixing financing costs into the operating line items.
If your inputs are monthly, multiply them by 12 before entering them so all figures are on an annual basis. Mixing monthly and annual amounts is one of the fastest ways to break NOI math.
Revisit NOI assumptions periodically, especially when property taxes are reassessed, insurance premiums jump, or utility rates change. Static expense lines can quietly erode returns if you do not update them.
This calculator does not break expenses into detailed line items, such as repairs versus capital improvements, or separate reimbursable expenses from non‑reimbursable ones. For full underwriting, you will still want a line‑item budget or spreadsheet.
It focuses on a simple three‑step model (gross income, less vacancy, less operating expenses) and does not handle more complex lease structures like percentage rent, triple‑net reimbursements with caps, or sophisticated expense stop arrangements.
NOI is an unlevered figure; it does not tell you anything about financing feasibility by itself. You still need to pair it with DSCR, loan‑to‑value, and cash‑on‑cash return analysis to understand lender and investor perspectives.
The results are sensitive to the quality of your vacancy and expense assumptions. Using overly optimistic inputs may produce a clean NOI that does not survive contact with real financial statements or lender underwriting.
Tax rules, accounting treatments, and lender guidelines can vary significantly by market and institution. Treat this tool as an educational aid and starting point, not as a substitute for professional advice.

Worked examples

Stabilized small multifamily with moderate expenses

Gross rental income (including parking and pet fees) is $120,000 per year. You apply a 5% vacancy allowance based on market data.
Vacancy cost = $120,000 × 0.05 = $6,000; Effective gross income = $120,000 − $6,000 = $114,000.
Operating expenses (taxes, insurance, repairs, management, common utilities, and reserves) total $35,000 per year.
Net operating income (NOI) = $114,000 − $35,000 = $79,000.
Expense ratio = $35,000 ÷ $114,000 ≈ 30.7%. This sits comfortably within a typical 30%–40% range for many stabilized small apartment properties.

Value‑add scenario with higher vacancy and lean expenses

A 10‑unit building has gross scheduled rent of $90,000, but you underwrite 8% vacancy to reflect planned turnover and lease‑up risk.
Vacancy cost = $90,000 × 0.08 = $7,200; Effective gross income = $90,000 − $7,200 = $82,800.
Operating expenses are budgeted at $30,000 while you execute renovations and stabilize the property.
NOI = $82,800 − $30,000 = $52,800; Expense ratio ≈ $30,000 ÷ $82,800 ≈ 36.2%.
You can then plug the $52,800 NOI into a cap rate or DSCR calculator to test post‑stabilization value and financing capacity under different exit scenarios.

Stress‑testing a broker pro forma with low expenses

A broker package shows gross income of $150,000 with only $40,000 of operating expenses and 3% vacancy—an expense ratio of roughly 27%.
You rerun the numbers in this calculator using a more conservative 6% vacancy and $55,000 of operating expenses based on your portfolio benchmarks.
Vacancy cost = $150,000 × 0.06 = $9,000; Effective gross income = $150,000 − $9,000 = $141,000.
NOI = $141,000 − $55,000 = $86,000; Expense ratio ≈ $55,000 ÷ $141,000 ≈ 39%.
The comparison highlights how sensitive NOI is to vacancy and expense assumptions and helps you explain to partners or lenders why your underwriting differs from the broker’s marketing numbers.

Deep dive

This NOI calculator walks you step by step from gross rental income to net operating income by applying a vacancy allowance and subtracting operating expenses, then surfaces vacancy cost, effective gross income, NOI, and an expense ratio you can benchmark against market norms.

Because it mirrors how lenders and appraisers think—NOI as income before debt service and taxes—you can drop the results directly into cap rate, DSCR, and value‑per‑unit analyses without rewriting the math each time.

Use it to sanity‑check broker pro formas, standardize underwriting across multiple deals, and quickly update NOI when taxes, insurance, or utility costs move, instead of rebuilding the logic from scratch in a spreadsheet every time.

FAQs

Does NOI include mortgage payments or other debt service?: No. By definition, NOI is calculated before any financing costs. Principal and interest payments on loans belong in debt service and are handled in DSCR or cash‑on‑cash return calculations, not in NOI.
Should I include capital expenditure (CapEx) reserves in operating expenses?: Many lenders and conservative investors do include a CapEx reserve line (for roofs, HVAC replacements, parking lot resurfacing, etc.) when underwriting NOI. If you want a more conservative figure, add a reasonable annual reserve amount to operating expenses before running the calculation.
Can I use monthly numbers instead of annual?: This calculator expects annual figures. If you only have monthly rent and expense data, multiply each item by 12 first so that gross income, vacancy, and expenses are all on the same annual basis before computing NOI.
Does NOI include property taxes, insurance, and utilities?: Yes. Property taxes, insurance, and any utilities you pay on behalf of the property are core components of operating expenses. The key is to separate them from debt service and owner‑specific costs like income taxes.
How is NOI different from EBITDA?: NOI is a real‑estate‑specific metric focused on property‑level income and expenses before financing and income taxes. EBITDA (earnings before interest, taxes, depreciation, and amortization) is a broader business metric that can include corporate‑level overhead and is not tied to a single property’s operating statement.
What NOI do lenders and appraisers look at?: Most lenders and appraisers prefer a stabilized NOI based on trailing financials adjusted for normal vacancy and a realistic expense load. They may also apply their own vacancy and expense assumptions regardless of the numbers you provide, which is why it is helpful to understand and model NOI the way they do.

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This net operating income (NOI) calculator is for educational and planning purposes only. It simplifies income and expense categories and relies on user‑entered vacancy and expense assumptions that may not match lender, appraiser, or tax definitions. Always verify income, expenses, and NOI with actual financial statements, market data, and qualified real estate, lending, or tax professionals before making purchase, financing, or disposition decisions.