Cap rate (capitalization rate) is the annual unlevered return a property would earn if bought entirely with cash — calculated as Net Operating Income (NOI) ÷ Value. On a $500,000 property with $32,500 NOI, the cap rate is 6.5% per year. It is the standard way to compare rental properties regardless of financing, down payment, or leverage, and to estimate value from income.
This in-depth guide explains what cap rate is, how to calculate it in three forms, how to derive NOI correctly (and the expenses most sellers omit), what a good cap rate is by property and market, how it differs from cash-on-cash and ROI, and the pitfalls that inflate NOI.
What Is Cap Rate?
Cap rate expresses a property's annual net income as a percentage of its value, assuming no debt. Formula: Cap Rate = Annual NOI ÷ Current Market Value (or purchase price when evaluating a deal). It answers: "If I paid cash, what annual return would the property's operations generate?"
Because it excludes financing, cap rate isolates property performance from the buyer's capital structure — a $500K property at 6.5% yields $32,500 NOI whether the buyer puts 20% down or pays cash. This makes it ideal for comparing a 4-unit in the suburbs with a downtown retail condo, regardless of loan terms. Per Investopedia: Cap Rate and Urban Institute housing research, cap rate is the primary income-approach metric for commercial and small multifamily valuation.
Why it matters beyond a single number: Rearranged, it values property: Value = NOI ÷ Cap Rate. If market cap for similar buildings is 6%, a building with $32,500 NOI is worth ~$541,667 at that market. Raising NOI by $8,000 at a 6.5% cap adds ~$123,076 in value ($8,000 ÷ 0.065) — which is why investors focus on rent, vacancy, and expense optimization.
Cap Rate Formula — 3 Ways to Use It
The same equation solves for different unknowns:
| Solve For | Formula | Example ($500K, $32.5K NOI) |
|---|---|---|
| Cap Rate | NOI ÷ Value | $32,500 ÷ $500,000 = 6.5% |
| Value | NOI ÷ Cap Rate | $32,500 ÷ 6% = $541,667 (at market 6%) |
| NOI Needed | Value × Cap Rate | $500,000 × 8% = $40,000 (for 8% target) |
Buying? Use NOI ÷ Value to judge if the cap is attractive versus market. Selling or appraising? Use NOI ÷ Cap Rate to estimate price at the market cap. Underwriting? Use Value × Cap Rate to see what NOI is required to hit a target return at a given price.
Annual, unlevered: Cap rate is annual and excludes debt. Use annual NOI (monthly NOI ×12) and market value. Never use cash flow after mortgage — that is a different metric (cash-on-cash) covered below.
How to Calculate NOI — Step-by-Step (With Example)
Accurate NOI is everything — a $7,500 overstatement at a 6.5% cap overvalues the property by ~$115,000. NOI is annual gross rental income minus vacancy/credit loss minus operating expenses, before debt service, income tax, depreciation, and financed capex.
Example — 4-Unit Building, $500,000 Value
- Gross rental income: 4 units × $1,500/mo ×12 = $72,000 per year if fully occupied. Add other income (laundry, parking, fees) to this line.
- Subtract vacancy and credit loss (5-10%): $72,000 × 5% = $3,600 → Effective Gross Income: $68,400. Use 5% for stable markets, 10% for higher-turnover or softer markets — sellers often assume 0% to inflate NOI.
- Subtract operating expenses: Property tax $6,000 + insurance $3,000 + maintenance $5,000 + property management $4,800 (7% of effective gross) + utilities (owner-paid) $3,600 + reserves $1,500 + HOA $0 = ~$23,900. In this example, total operating expenses of $35,900 are used to illustrate a full load: $68,400 − $35,900 = NOI $32,500.
What Counts as Operating Expense vs What Doesn't
| Included in NOI ✓ | Excluded from NOI ✗ |
|---|---|
| Property tax, insurance, maintenance & repairs, property management, utilities (owner-paid), HOA, reserves for replacement, marketing/leasing | Mortgage (principal + interest), income taxes, depreciation, capital expenditures that are financed, owner draws, personal expenses |
Cap rate excludes debt because it is a financing choice — the same property should have the same cap whether the buyer finances 0% or 80%. Cash flow after debt service is a separate, levered metric.
Common NOI mistake: Using cash flow after mortgage as NOI. A property with $32,500 NOI and $18,000 annual debt service has $14,500 cash flow. $14,500 ÷ $500,000 = 2.9% is not the cap rate — it is cash-on-cash before other adjustments. The cap rate remains $32,500 ÷ $500,000 = 6.5%.
What Is a Good Cap Rate? — By Property and Market
| Cap Rate | Meaning | Typical Property / Market | Risk / Return |
|---|---|---|---|
| 3-5% (Low) | Expensive, stable | Prime NYC/SF, Class A, long leases, low vacancy | Low risk, low current yield |
| 5-7% (Mid) | Balanced | Suburban multifamily, Class B, stable market | Moderate — most investors target 6-8% |
| 8-10% (High) | Cheap, higher yield | Class C, tertiary market, value-add, higher vacancy | Higher risk, higher yield |
| 10%+ (Very High) | Distressed / speculative | Heavy rehab, high vacancy, or overpriced low-cap bubble | High risk — verify NOI thoroughly |
A "good" cap is relative: an 8% cap in a tertiary market may be riskier than a 5% cap in a prime market with 2% vacancy and rent growth. Cap rate measures current income yield, not appreciation, capex, or 10-year IRR — it is a snapshot, not a total return.
Cap Rate vs Cash-on-Cash vs ROI/IRR
- Cap rate (unlevered):
NOI ÷ Value• No debt • 6.5% at $500K, $32.5K NOI • Compares properties irrespective of financing - Cash-on-cash (levered):
Annual cash flow ÷ Cash invested• Includes debt service • Higher than cap when cap exceeds interest rate (positive leverage). Same property with 20% down, 7% loan → ~9% cash-on-cash - ROI / IRR (total): Includes appreciation, tax benefits, principal paydown, and sale proceeds • Cap is income only
Leverage boosts return when cap rate exceeds the interest rate; it drags when below. Cap rate isolates the property; cash-on-cash shows the equity return with the chosen financing.
Cap Rate Pitfalls — What Inflates NOI
- Inflated NOI: Seller shows NOI $40,000 using $72,000 gross (no vacancy) and low expenses → "8%" on $500K looks great. True NOI $32,500 → real cap 6.5% → overpriced by ~$115,000 at the claimed cap. Always underwrite with 5-10% vacancy and realistic reserves.
- Using cash flow as NOI: $32,500 NOI − $18,000 mortgage = $14,500 cash flow.
$14,500 ÷ $500K = 2.9%is not the cap — cap is before debt. This mistake understates the property's income performance. - Pro forma vs trailing NOI: Pro forma projects future rents and lower expenses; trailing 12-month (T12) shows actuals. Underwrite to T12 and verify leases, then haircut pro forma by at least 10%.
- Ignoring capex reserves: Omitting reserves ($200-300/unit/year) overstates NOI by 2-4%; lenders and appraisers include them.
How to Use the Cap Rate Calculator — 3 Modes
- Find cap rate: Enter annual NOI and value/price — e.g., $32,500 ÷ $500,000 = 6.5%. Use when buying to compare to market cap.
- Find value: Enter NOI and market cap — e.g., $32,500 ÷ 6% = $541,667. Use when pricing a listing at the prevailing cap or testing a seller's ask.
- Find NOI: Enter value and target cap — e.g., $500,000 × 8% = $40,000 annual NOI needed to hit 8% at that price. Use when underwriting a required rent or expense level.
For NOI, the calculator can sum it from gross rent, vacancy %, and individual expenses, or accept NOI directly. This avoids manual spreadsheet errors and makes the vacancy and expense assumptions explicit.
Value trick: Small NOI changes create large value changes at low caps. Raising NOI by $8,000 at a 6.5% cap adds ~$123,076 in value ($8,000 ÷ 0.065). This is why value-add investors focus on rent increases, vacancy reduction, and expense control — each dollar of NOI is multiplied by 1/cap.
Cap Rate Beyond the Snapshot — Limitations
- Ignores financing: Two properties with the same cap can have different cash-on-cash due to leverage. Use DSCR (NOI ÷ Debt Service) alongside cap to test loan feasibility — lenders typically require DSCR ≥ 1.2.
- Ignores rent growth and vacancy change: A 5% cap with 3% annual rent growth may beat an 8% cap with flat rents over 10 years. Run a 10-year pro forma IRR for total return.
- Ignores capex and appreciation: Cap is current income yield, not including renovation costs or future sale price. Add capex to the model for value-add deals.
- Market cap moves: Rising interest rates often push cap rates up (values down). A 6.5% cap today may be 7.5% next year if rates rise — the same NOI would imply a lower value.
FAQs About Cap Rate
What is cap rate in real estate?
Cap rate is the annual unlevered return a property would earn if bought with cash, calculated as Annual NOI ÷ Value. A 6.5% cap on a $500,000 property means $32,500 NOI per year.
How do you calculate cap rate?
Divide annual NOI by property value or price. Example: $32,500 NOI ÷ $500,000 = 6.5%. Rearranged: Value = NOI ÷ Cap Rate; NOI = Value × Cap Rate.
What is a good cap rate?
It depends on risk and market: 3-5% for prime, stable Class A; 5-7% for balanced suburban multifamily (most investors target 6-8%); 8-10% for higher-yield Class C or tertiary markets; 10%+ is very high and requires verifying NOI.
What is the difference between cap rate and cash-on-cash return?
Cap rate is NOI ÷ Value with no debt (unlevered). Cash-on-cash is annual cash flow after debt service ÷ cash invested, including leverage. Cash-on-cash exceeds cap when the cap exceeds the interest rate.
Does cap rate include mortgage payments?
No — NOI and cap rate exclude mortgage payments. Cash flow after debt service and ROI include them separately.
How do I value a property using cap rate?
Divide the property's annual NOI by the prevailing market cap rate for similar properties: e.g., $32,500 ÷ 6% = $541,667 at a 6% market cap. Verify NOI with 5-10% vacancy and realistic expenses, not pro forma.
Conclusion
Cap rate is the starting point for income-property analysis — a clean, financing-free way to compare properties and translate income into value. Calculate NOI rigorously, compare the cap to the market for that property class and location, and then layer cash-on-cash, DSCR, and a 10-year IRR to see the full picture beyond the snapshot.
Enter NOI and value (or price) to get the cap rate instantly — or solve for value or required NOI to test the asking price and underwriting assumptions before making an offer.
