How to Calculate Cap Rate: Formula, Examples, and What It Means

Capitalization rate, almost always shortened to cap rate, is the single most quoted number in commercial and rental real estate. It tells you the unleveraged annual return a property would produce if you bought it outright with cash. Because it strips out financing and looks only at the income the building generates against its price, it gives a clean apples to apples way to compare very different properties. This guide walks through the formula, defines net operating income carefully, hands you a worked example and a reference table, and explains what a high or low cap rate actually signals.

What cap rate actually means

Cap rate is the ratio between a property's net operating income and its value, written as a percentage. If a building earns 30,000 a year in net operating income and is worth 500,000, the cap rate is 6 percent. You can read that as the cash yield a cash buyer would earn in the first year before any mortgage. It is the real estate cousin of a stock's earnings yield, and it lets you line up a four unit rental, a strip mall, and an office building on the same scale.

The key word is unleveraged. Cap rate deliberately ignores your mortgage, your down payment, and your taxes so it can describe the asset itself rather than your particular financing. That is what makes it useful for comparison. Once you layer in a loan, your actual cash on cash return will differ, but the cap rate stays a property of the building and its price.

The cap rate formula

The formula has only two inputs, and you can rearrange it depending on what you know. Use the first version to find the return from a known income and price. Use the others to back into a value or a required income.

• Find the cap rate: cap rate = net operating income / property value x 100
• Find the value: property value = net operating income / cap rate
• Find the income: net operating income = property value x cap rate

Every version pivots on net operating income, so the whole calculation lives or dies on getting that number right. The second version is how appraisers and brokers value income property: take a stabilized income and divide by a market cap rate to estimate what a building is worth. If you want to brush up on the underlying division, our walk through on how to calculate percentage covers the mechanics.

What net operating income includes

Net operating income, or NOI, is gross rental income minus operating expenses. It is the part of the calculation people get wrong most often, so be precise. NOI does not subtract your mortgage payment, and it does not subtract income tax. Those are financing and personal items, not costs of running the building, so they stay out of the cap rate.

• Include in income: all rent collected, plus parking, laundry, storage, and other recurring property income, adjusted down for expected vacancy.
• Include in expenses: property taxes, insurance, property management, repairs and maintenance, utilities you pay, and reserves.
• Exclude from expenses: mortgage principal and interest, income tax, depreciation, and one off capital improvements.

In short, NOI is the profit the building throws off from operations, before you decide how to finance it. Keeping mortgage payments out is exactly what lets two investors with different loans compare the same property fairly. This is closely related to operating profit in any business, much like the figure covered in how to calculate net income, except cap rate stops before financing and tax.

Worked example, step by step

Suppose you are looking at a small rental property listed at 400,000. It collects 36,000 a year in rent, and you expect 6,000 a year in operating expenses for taxes, insurance, and upkeep. Here is how to find the cap rate.

1. Start with gross annual income: 36,000.
2. Subtract operating expenses to get NOI: 36,000 minus 6,000 equals 30,000. Note that no mortgage is subtracted.
3. Confirm the value or price you are testing against: 400,000.
4. Divide NOI by value: 30,000 divided by 400,000 equals 0.075.
5. Multiply by 100 to convert to a percentage: 0.075 x 100 equals 7.5 percent.

This property has a 7.5 percent cap rate. Now use the formula in reverse. If similar buildings in the area trade at a 6 percent cap rate, what is this NOI worth at market? Divide 30,000 by 0.06 to get 500,000. The same income looks like a 400,000 deal at a 7.5 percent cap rate or a 500,000 asset at a 6 percent cap rate, which shows why the cap rate you apply matters so much.

Reading a high or low cap rate

A higher cap rate signals higher potential return but usually higher risk, while a lower cap rate signals a pricier, often safer asset. A 9 percent cap rate property might sit in a secondary market, carry older tenants, or need work, all of which push the price down relative to income. A 4 percent cap rate property is often a newer building in a prime location with stable tenants, where buyers accept a lower yield for safety and growth.

So a high cap rate is not automatically a better deal, and a low one is not automatically overpriced. The number reflects how the market prices the risk, location, and quality of that specific property. The table below shows how the same NOI maps to very different values depending on the cap rate the market applies.

Common mistakes to avoid

The cap rate math is simple, but the inputs trip people up. Watch for these errors before you trust a number.

• Subtracting the mortgage from NOI. Cap rate is unleveraged. Including loan payments turns it into a cash flow figure and makes properties look incomparable.
• Forgetting vacancy. Using full asking rent with zero vacancy inflates NOI and your cap rate. Build in a realistic vacancy allowance.
• Leaving out real expenses. Skipping management, reserves, or rising insurance makes the return look better than it is.
• Comparing across different markets blindly. An 8 percent cap rate in one city and a 5 percent cap rate in another can both be fair given local risk and growth.
• Using listing price instead of true value. A seller's asking price is not always market value, so the cap rate it produces may be optimistic.

Good to know

Cap rate is a first year snapshot, not a full return. It ignores appreciation, loan paydown, rent growth, and tax benefits, all of which can make the real long term return higher than the cap rate suggests. For a leveraged view, investors pair cap rate with cash on cash return and internal rate of return.

Cap rate also moves with interest rates. When borrowing gets more expensive, buyers demand higher cap rates, which pushes prices down for the same income. That inverse link to value is why tracking cap rate trends matters, and you can frame those shifts using ideas from percent change. To run your own numbers instantly, use the calculator below.

Master the cap rate formula and you have a fast, reliable lens for sizing up income property. Start with a clean net operating income, keep your mortgage and taxes out of it, divide by a realistic value, and read the result in the context of market risk and location. With those habits, you can compare deals on equal footing and spot when a price truly makes sense.