Cap Rate Calculator

The cap rate calculator focuses on one real estate question: how much annual net operating income does the property produce relative to its price? Enter the property value and annual NOI, and the results include the capitalization rate, monthly NOI equivalent, and an illustrative value if that same NOI were priced at a 6 percent cap rate. This page is intentionally narrower than a full rental analysis. It is about NOI divided by price, not mortgage payments, taxes on the investor, depreciation schedules, or appreciation forecasts.

Cap rate is popular because it lets investors compare income-producing property before financing choices distort the picture. A duplex bought with cash and the same duplex bought with 75 percent debt should have the same cap rate if the purchase price and NOI are unchanged. The buyer using debt will care about loan terms later, but the first underwriting pass asks whether the property income supports the price. For a broader cash-flow model that does include debt service, use the rental property ROI calculator. If you are screening gross rent before expenses, compare this result with the gross rent multiplier calculator. For financing sensitivity, use the mortgage calculator.

What cap rate means

Capitalization rate is the annual income yield of the real estate itself. The numerator is net operating income: rent and other recurring property revenue after vacancy and operating expenses. The denominator is the value or price being tested. A 7 percent cap rate says that annual NOI equals 7 percent of the property’s value. It does not promise that the investor will earn 7 percent after loan payments, income taxes, closing costs, future repairs, or sale proceeds.

Cap rates are market specific. A stabilized apartment building in a supply-constrained city may sell at a lower cap rate than a rural single-tenant building because investors accept less current yield for perceived stability or growth. A higher cap rate can be attractive when it comes from strong income at a fair price, but it can also be a warning that tenants are risky, roofs are old, leases are short, or local demand is weak. Treat the number as a starting point for questions, not the final answer.

Formula

The calculator uses the standard unlevered cap rate formula:

$\text{cap rate} = \frac{\text{net operating income}}{\text{property value}} \times 100$

It also rearranges the relationship for a 6 percent value check:

$\text{value at 6 percent} = \frac{\text{net operating income}}{0.06}$

Monthly NOI equivalent is simply annual NOI divided by 12:

$\text{monthly NOI} = \frac{\text{net operating income}}{12}$

Example: calculating a cap rate

Using the default inputs, suppose a property is valued at $600,000 and produces $42,000 of annual net operating income. The cap rate calculation is:

$\text{cap rate} = \frac{\text{\$42,000}}{\text{\$600,000}} \times 100 = 7\%$

The monthly NOI equivalent is $42,000 divided by 12, or $3,500. The calculator also shows a value at 6 percent by dividing $42,000 by 0.06, which equals $700,000. That does not mean the property is automatically worth $700,000; it means that if the market accepted a 6 percent yield for this exact NOI, the income stream would support that price. At the entered $600,000 value, the property has a higher 7 percent current income yield.

This example also shows why cap rate is sensitive to both sides of the fraction. If NOI falls to $36,000 while the price stays $600,000, the cap rate drops to 6 percent. If NOI stays $42,000 but the asking price rises to $700,000, the cap rate also becomes 6 percent. Price and income must be reviewed together.

Investor context and benchmarks

Investors often use cap rate in three ways. First, it is a quick screen: if similar buildings in the same neighborhood trade near 6 percent and the listing shows 4 percent, the asking price may be aggressive or the future growth story needs to be strong. Second, cap rate is a negotiation language. Buyers can explain their offer by showing the NOI they believe is sustainable and the market cap rate they believe is appropriate. Third, it is a stress test. Raising expenses, vacancy, or reserves lowers NOI and reveals how quickly the deal stops meeting a target yield.

Benchmarks should be local and property-specific. Compare apartment to apartment, retail to retail, and stabilized property to stabilized property. Do not use a national average as a rule for a single duplex. Local rent trends, property taxes, insurance availability, zoning, tenant quality, lease terms, and deferred maintenance can all justify differences. When reviewing an offering memorandum, rebuild NOI from source documents instead of relying only on the seller’s pro forma. A small expense omission can move the cap rate enough to change the investment decision.

Practical tips

• Use current or supportable market rent, not a best-case rent that has not been achieved.
• Include vacancy, management, repairs, insurance, property tax, owner-paid utilities, and ordinary reserves in NOI.
• Keep mortgage payments out of NOI so the ratio remains comparable across buyers.
• Review at least one conservative case with higher vacancy or repairs before making an offer.
• Pair cap rate with cash flow, debt coverage, tenant quality, and exit value rather than treating it as a complete investment score.

Informational note

This calculator is for education and deal screening. It is not an appraisal, investment recommendation, tax opinion, or lending decision. Real estate returns depend on local law, financing terms, property condition, tenant behavior, insurance, taxes, and resale markets. Confirm assumptions with leases, tax bills, insurance quotes, inspection reports, lender terms, and qualified advisers before committing capital.

Sources

• IRS, Publication 527: Residential Rental Property — rental income and expense concepts used when documenting residential rental property.
• IRS, Publication 946: How to Depreciate Property — distinguishes operating analysis from depreciation and capital recovery rules.
• National Association of Realtors, Research and Statistics — housing market research context for comparing real estate conditions.