Cap Rate Explained: How Real Estate Investors Evaluate a Deal
Jordan Caldwell
Lead Developer, Blueprint Dynamics
Cap rate is the most widely used metric in real estate investment — and one of the most misunderstood. Here's what it actually measures, how to calculate it correctly, and when to rely on it versus when to look at other metrics.
Capitalization rate — cap rate — is defined as net operating income (NOI) divided by property value, expressed as a percentage. It answers one specific question: if you paid all cash for this property, what is your annual return on investment? No mortgage, no leverage, no financing — just the property's income relative to its cost. That simplicity makes it powerful for comparing properties across markets, property types, and price points.
The formula and a worked example
Net Operating Income = gross rental income − vacancy allowance − operating expenses. Operating expenses include property taxes, insurance, property management fees, maintenance and repairs, capital expenditure reserves, and utilities you pay. Mortgage payments are NOT included in operating expenses — NOI is pre-financing. Example: A duplex generates $36,000/year in gross rent. Assuming 5% vacancy ($1,800), $8,200 in operating expenses (taxes, insurance, management, maintenance): NOI = $36,000 − $1,800 − $8,200 = $26,000. At a purchase price of $380,000: cap rate = $26,000 ÷ $380,000 = 6.8%.
What's a good cap rate?
There is no universal answer — cap rate norms vary by market and property type. In high-appreciation urban markets (San Francisco, Manhattan, Boston), 4–5% cap rates are common because buyers accept lower current yield in exchange for expected appreciation. In Midwest and Sun Belt markets, 7–9% cap rates are typical. Commercial properties (multifamily, retail, industrial) each have their own cap rate norms. Compare cap rates within a specific market and asset class, not across them. A 5% cap rate in New York City and a 5% cap rate in rural Ohio are not equivalent opportunities.
Cap rate vs. cash-on-cash return
Cap rate ignores financing. Cash-on-cash return doesn't. Cash-on-cash = annual pre-tax cash flow (after mortgage payments) ÷ total cash invested (down payment + closing costs + immediate repairs). A property with a 7% cap rate financed at 7.5% interest produces negative cash-on-cash return — the debt service exceeds NOI. In a high-rate environment like 2025–2026, the cap rate/interest rate spread is particularly important. A property needs a cap rate meaningfully above your mortgage rate to produce positive cash flow with leverage.
When cap rate has limitations
Cap rate is a snapshot, not a full investment analysis. It doesn't account for: appreciation or depreciation in property value over time, value-add potential from rent increases or renovations, tax benefits (depreciation, 1031 exchanges), or financing terms that can make the same property more or less attractive. It also depends entirely on the accuracy of your NOI estimate — sellers often present pro-forma NOI based on potential rather than actual income. Always calculate NOI using current actual rents and documented actual expenses, not the seller's projections.
Use the free calculators
More articles
How to Calculate a Calorie Deficit That Produces Real Results
A calorie deficit is the only reliable mechanism for fat loss. Here's how to calculate yours correctly, choose a sustainable deficit size, and avoid the common mistakes that stall progress or cause muscle loss.
HealthWhat BMI Actually Measures — And What It Doesn't
BMI is one of the most used and most misunderstood health metrics. Here's an honest breakdown of what it measures, where it fails, and what additional metrics give a more complete picture of health.