Deal Analysis

Cap Rate Calculator: What It Is and How to Use It

Two investors look at the same $400,000 rental property. One sees a solid deal. The other walks away. The difference isn't instinct—it's that one of them ran the cap rate and actually understood what it was telling them.

9 min read Updated June 2025 Informational only — not financial or investment advice

Table of Contents

What Is Cap Rate in Real Estate?
The Cap Rate Formula
How to Calculate Net Operating Income
A Real-World Cap Rate Calculation
What Is a Good Cap Rate?
Cap Rate vs. Rental Yield: What's the Difference?
How Cap Rate Is Used to Value Properties
Cap Rate Calculator — Free Tool
The Biggest Cap Rate Mistakes Investors Make
FAQ

What Is Cap Rate in Real Estate?

Cap rate measures the relationship between a property's net operating income (NOI) and its current market value or purchase price. Strip away everything else and it answers one question: if you paid cash for this property, what annual return would you earn from operations alone?

It's expressed as a percentage. A property generating $30,000 in NOI purchased for $400,000 has a cap rate of 7.5%—the return on the asset, before debt, before depreciation, before your personal tax situation enters the picture.

What Cap Rate Measures

NOI ÷ Value

Income return on a property's value — financing excluded. A pure asset-level metric.

Why Financing Is Excluded

Apples to Apples

Cap rate lets you compare a duplex in Columbus to a fourplex in Tucson without debt structure distorting the picture.

The Cap Rate Formula

The math is clean and uncomplicated. The real work isn't in the formula — it's in calculating NOI accurately.

Cap Rate Formula

Cap Rate = (Net Operating Income ÷ Property Value) × 100

Quick example: $30,000 NOI on a $400,000 property
Cap Rate = ($30,000 ÷ $400,000) × 100 = 7.5%

Implied Value Formula (Reverse Cap Rate)

Property Value = NOI ÷ Cap Rate

Quick example: $30,000 NOI, 6% market cap rate
Implied Value = $30,000 ÷ 0.06 = $500,000

How to Calculate Net Operating Income

NOI is your annual rental income minus all operating expenses. The key word is operating — mortgage payments are excluded. Cap rate is a property-level metric, not an investor-level one.

This is where most investors either get it right or quietly fool themselves. Here's what goes into an accurate NOI:

❌ Not Included in NOI

Financing Costs

Mortgage P&I payments are excluded. So is debt service of any kind. Cap rate evaluates the asset, not the financing structure.

✅ Included in NOI

All Operating Expenses

Taxes, insurance, management, repairs, vacancy losses, utilities, HOA, landscaping — everything it costs to run the property.

A Real-World Cap Rate Calculation

Let's walk through a full example from gross rent down to cap rate using a small fourplex in a mid-size Southeastern market.

📐 Fourplex — $520,000 Asking Price Step-by-Step

Income

Monthly Gross Rent (4 units × $1,050)$4,200 / mo

Annual Gross Rental Income$50,400 / yr

Vacancy Allowance (7%)− $3,528

Effective Gross Income (EGI)$46,872

Operating Expenses

Property Taxes− $5,200

Insurance− $2,100

Property Management (10%)− $4,687

Maintenance & Repairs (1% of value)− $5,200

Misc / Landscaping− $800

Net Operating Income (NOI)$28,885

Cap Rate ($28,885 ÷ $520,000)5.55%

What Is a Good Cap Rate?

There's no single "good" cap rate number — and anyone who gives you one without context is oversimplifying. Cap rates are market-relative, asset-class-relative, and strategy-relative. The question isn't whether 5.55% is "good" in the abstract — it's whether 5.55% is good for this market, this asset class, and your investment goals.

Market Type	Example Cities	Typical Cap Rate	Key Tradeoff
High-cost metros	NYC, LA, San Francisco	3.0 – 4.5%	Low yield, strong appreciation & stability
Mid-tier cities	Denver, Austin, Nashville	4.5 – 6.5%	Balanced — moderate yield & appreciation
Secondary markets	Memphis, Indianapolis, Birmingham	6.5 – 10%	Higher cash yield, higher risk profile
Tertiary/distressed	Cleveland, Detroit sub-markets	9 – 12%+	Maximum yield, maximum management demands

Typical Cap Rate Ranges — Visualized

San Francisco / NYC

High-cost metro

3–4.5%

Austin / Nashville

Mid-tier growth

4.5–6.5%

Indianapolis / Memphis

Secondary market

6.5–10%

Detroit sub-markets

Tertiary / distressed

10–12%+

⚠️ Higher cap rate ≠ better deal. A 10% cap rate in a tertiary market isn't automatically a great deal — that premium compensates for elevated vacancy risk, deferred maintenance, and management intensity. Always ask why other buyers haven't already bid the cap rate down.

Cap Rate vs. Rental Yield: What's the Difference?

These two metrics are related but not interchangeable, and confusing them is a real problem in deal analysis.

📊 Rental Yield (Gross)

Annual Rent ÷ Purchase Price

Quick filter metric. Does not account for operating expenses. Useful for initial screening — not for underwriting. Can significantly overstate actual returns.

📈 Cap Rate

NOI ÷ Property Value

Uses income after expenses. More accurate picture of a property's earning power. The metric serious investors rely on for actual deal evaluation.

If someone quotes you a rental yield without referencing expenses, you're looking at an incomplete picture. Cap rate is the more rigorous metric for any serious deal analysis.

How Cap Rate Is Used to Value Properties

Here's something investors often overlook: cap rate isn't just a measurement tool — it's a valuation tool. If you know the prevailing cap rate in a market for a given property type, you can work the formula backwards to estimate what a property should sell for based on its income.

Say comparable fourplexes in your target market are trading at a 6% cap rate. If your subject property generates $30,000 in NOI:

Implied Value Check

$30,000 ÷ 0.06 = $500,000 implied value

Listed at $540,000? Overpriced vs. market cap rates · Listed at $460,000? Potential opportunity — or a reason to dig deeper into why it's discounted.

This reverse calculation is how commercial appraisers and institutional buyers think about value. It's also how you can quickly sanity-check any asking price against market reality before spending time on due diligence.

📊

Cap Rate Calculator

Free · Instant · No sign-up

Full tool →

The Biggest Cap Rate Mistakes Investors Make

Knowing the formula is easy. Applying it honestly is harder. These are the errors that turn a promising deal analysis into a costly miscalculation.

Using seller-provided income figures without verification

Always check rent rolls against local comps, and request 12 months of bank statements if you're buying an occupied property. Pro formas that show 100% occupancy for 24 months straight are a red flag, not reassurance.

Forgetting to include management costs

Even self-managing landlords should model management fees (8–12%). If the deal only works because you're doing every task yourself, it's not a scalable investment — it's a second job. Model it as if you hired someone.

Ignoring capital expenditure reserves

CapEx — roof, HVAC, appliances, plumbing — isn't technically an operating expense, but it's real money leaving your account. Many conservative analysts add a CapEx reserve line to NOI to get a more accurate picture of true earnings power.

Applying a national "good cap rate" instead of a local benchmark

A 6.5% cap rate in Indianapolis is meaningful when benchmarked against comparable Indianapolis properties — not against a San Diego fourplex. Context is everything. Know your market comparables before drawing conclusions.

FAQ: Cap Rate Questions Investors Ask Most

Does cap rate include mortgage payments?

No. Cap rate is calculated using NOI, which excludes all financing costs. That's intentional — it lets you evaluate the property as an asset regardless of how it's financed. For a return metric that includes debt service, use cash-on-cash return instead.

Can cap rate change after I buy a property?

Yes, in two ways. If you increase NOI — through higher rents or reduced expenses — your cap rate on cost improves. And if market cap rates shift (as they do when interest rates and demand change), the implied market value of your property moves with them. This is how real estate "cap rate compression" creates value without the owner doing anything.

What cap rate should I target as a first-time investor?

Most experienced investors suggest targeting a cap rate at least 1–2% above the prevailing market rate for your asset class — that margin gives you a buffer against unexpected expenses and vacancy. Where that lands numerically depends heavily on your local market. Know the comparable sales before setting a target.

Is a higher cap rate always better?

Not automatically. Higher cap rates compensate for higher risk. Before celebrating a 10% cap rate, ask why other buyers haven't already bid it down. There's usually a reason — high vacancy, deferred maintenance, neighborhood trajectory, or management intensity. The cap rate is a signal worth investigating, not a score to maximize blindly.

How often should I recalculate cap rate on properties I already own?

Annually, at minimum. Rents, taxes, insurance, and expenses all shift over time. Knowing your current cap rate on a property you already own tells you whether it's still performing — and informs decisions about refinancing, selling, or deploying capital elsewhere.

Free — no account required

Run the Numbers Before You Make an Offer

Cap rate isn't a guarantee of anything — it's a starting point. But it's one of the most reliable starting points available for cutting through listing hype and evaluating what a property is actually worth as an income-producing asset.

Open Cap Rate Calculator → Rental Yield Calculator →

Continue Reading

NOI & Expenses

How to Calculate Net Operating Income for a Rental Property

A line-by-line guide to building an accurate NOI — the number that makes or breaks every cap rate calculation.

Metric Comparison

Rental Yield vs. Cap Rate — Which Metric Should You Use and When?

Both measure property income. Here's how they differ, when each matters, and why confusing them costs investors money.

Due Diligence

Pro Forma Red Flags: How to Spot Inflated Income Projections Before You Buy

The numbers sellers show you aren't always the numbers you'll actually see. Here's what to look for before signing anything.