What is a cap rate in real estate?

Ask an investor about a property and the first question back is usually "what's the cap rate?" If you can't answer in one sentence, the conversation is already over.

This guide covers what a cap rate is, the formula with a worked example, what counts as a good cap rate, when the metric lies to you, and how agents use it to sound like the investor's equal instead of their order-taker.

What is a cap rate in real estate?

A cap rate is a property's annual net operating income divided by its price, expressed as a percentage. Capitalization rate, or cap rate, is the return a property would produce in a year if you bought it with cash, before financing and income taxes.

A 6% cap rate means the property's operations earn 6% of its price per year. Because the mortgage is left out, cap rate measures the property itself, not any particular buyer's loan. That's what makes it the standard tool for comparing income properties head to head, and it's why appraisers, lenders, and every serious investor lean on it.

How do you calculate a cap rate?

To calculate a cap rate, divide the property's net operating income by its purchase price, then multiply by 100.

Cap rate = (NOI ÷ property price) × 100

Take a small apartment building earning $100,000 in net operating income with a $1.25 million asking price. $100,000 ÷ $1,250,000 = 0.08, an 8% cap rate. The formula also rearranges into the two versions investors actually use most:

1. Price a property: value = NOI ÷ market cap rate. If similar buildings trade at a 6% cap and this one earns $100,000, it's worth about $1.67 million.
2. Check the income a price implies: NOI = value × cap rate. A seller asking $2 million at a claimed 6% cap is promising $120,000 of NOI. Rebuild the NOI yourself and see if it's real.

That second move is the whole game. At a 6% cap, every $1,000 of NOI is worth roughly $16,700 of price, so sellers have every incentive to pad the income and skip expenses. Trust the formula, verify the inputs.

What is a good cap rate for a rental property?

Most stabilized rentals trade somewhere between roughly 4% and 10%, and the right number depends on the market and the risk. There's no universal good cap rate.

The pattern to remember: low cap rates mean expensive, lower-risk, high-demand markets, and high cap rates mean cheaper properties with more risk or rougher condition. A 4.5% cap in a coastal metro can be a strong buy, and a 12% cap in a shrinking town can be a trap. Compare a property's cap rate against similar buildings in the same submarket, not against a national figure. For current market-level numbers, CBRE publishes a recurring cap rate survey worth bookmarking.

Higher isn't automatically better. A higher cap rate is the market charging you for risk: weaker tenants, deferred maintenance, or a declining area. The question isn't "how high?" It's "is the extra return worth what's causing it?"

Cap rate vs GRM vs cash-on-cash return: what's the difference?

Cap rate measures unleveraged return on price, the gross rent multiplier is a faster screen that ignores expenses, and cash-on-cash return measures the return on the actual cash a financed buyer puts in. Three tools, three jobs.

MetricFormulaWhat it's forGross rent multiplierPrice ÷ annual gross rent10-second screen to rank a long listCap rateNOI ÷ priceComparing properties on equal footing, no financingCash-on-cash returnAnnual pre-tax cash flow ÷ cash investedJudging a financed deal for a specific buyer

In the USRT Three-Number Deal Check, the gross rent multiplier screens, the cap rate confirms, and ROI closes. Cap rate is the confirm step because it's the first number in the sequence that uses real expenses. [CASH-ON-CASH LINK SLOT: when the cash-on-cash article publishes, link "Cash-on-cash return" in the table's third row label or in the paragraph above to /blogs/cash-on-cash-return.]

When should you not use a cap rate?

Don't lean on cap rate for flips, for properties without stabilized income, or for judging a financed return. The metric assumes steady operations and an all-cash lens.

• Flips: a house mid-renovation has no stabilized NOI. Work from after repair value instead.
• Single-family rentals with thin data: one tenant and owner-paid utilities make NOI estimates shaky. Cap rate still works, but treat it as rough.
• Financed buyers who ask "what do I earn on my cash?": that's a cash-on-cash question, not a cap rate question.

How do agents use cap rates with investor clients?

Agents use cap rates to translate price into income and income into price, on the spot. That's the skill investor clients test you on.

Run the 10-minute deal screen on a listing before the showing: rebuild the NOI from the listing's numbers, divide by the ask, and compare against the submarket. Walking in, you already know whether the price implies a 5% cap in a 6.5% neighborhood. Say that out loud to an investor and you've separated yourself from every agent who led with the kitchen finishes.

The takeaway

Cap rate is NOI divided by price: the property's unleveraged annual return and the fastest honest way to compare income deals. Learn the two rearrangements, value from income and income from value, and you can sanity-check any listing in under a minute. The formula is easy. The edge is rebuilding the NOI instead of taking the flyer's word for it.

Be the agent who answers the cap rate question

When an investor asks "what's the cap rate?", the agents who win say the number and then explain what's behind it. The Certified Investor Agent Specialist (CIAS) course drills cap rate, cash flow, and 1031 fundamentals with calculators and scripts built for those exact conversations. Try the CIAS course free for 3 days. No payment, full first chapter, instant access.