Cap Rate Calculator

Find a property's capitalization rate from its income and price.

Details

$
Income
$
$
%

Cap rate

6.32%

Gross rent (a year)$40,800
Less vacancy− $2,040
Collected rent$38,760
Less operating expenses− $13,477
Net operating income$25,283

Monthly NOI

$2,107

Expense ratio

34.8%

This works out the capitalisation rate on a rental property: the annual return it produces relative to its price, ignoring financing.

Enter the price and either the net operating income directly or the rent and expenses, and it returns the cap rate along with the NOI it was based on.

What a cap rate is

Cap rate is the annual net operating income divided by the property's price or value, as a percentage. A property earning $18,000 a year after expenses, priced at $400,000, has a 4.5% cap rate.

Its purpose is comparison. Because it deliberately ignores how the deal is financed, two properties can be compared on their own merits regardless of who is borrowing what.

That is also its limitation. Cap rate says nothing about your actual cash flow, because your mortgage is not in it. For that you want cash-on-cash return instead.

$18,000 net income on a $400,000 property
$18,000net operating income
÷
$400,000price or value
=
4.5%cap rate

NOI is rent minus operating expenses, but NOT minus the mortgage. Financing is deliberately excluded so the property can be judged separately from the buyer.

What to enter

Property value / price
The purchase price, or current market value if you already own it. Cap rate on what you paid years ago tells you little about today.
Annual NOI
Net operating income. Enter it directly if you have it, or use the rent and expense fields to build it up.
Monthly rent and other income
Gross rent plus anything else the property earns: parking, laundry, storage.
Vacancy rate
The share of the year you expect the property to sit empty. Assuming zero is the fastest way to an unrealistic cap rate.
Operating expenses
Tax, insurance, management, repairs, maintenance and any utilities you pay. Not the mortgage.

What belongs in NOI, and what does not

Include: property tax
A genuine ongoing cost of owning the asset.
Include: insurance, management, repairs
Including management even if you self-manage, since your time is not free.
Include: vacancy allowance
Deducted from gross rent before expenses. 5-8% is common.
Exclude: mortgage payments
The most common error. Financing is specific to you, not to the property.
Exclude: depreciation
An accounting entry, not cash leaving your pocket.
Exclude: capital improvements
A new roof is an investment in the asset, not an operating cost.

What this assumes

Income and expenses are stabilised annual figures, not one unusually good or bad month.

Cap rate is a snapshot at today's numbers. It says nothing about rent growth, appreciation or how the market moves.

How to calculate a cap rate

Build the NOI carefully, then divide. Almost every bad cap rate comes from a sloppy NOI rather than the division.

cap rate = net operating income ÷ property value × 100
net operating income
Rent, minus vacancy, minus operating expenses
property value
Purchase price or current market value
  1. Start with gross annual rent. Monthly rent × 12, plus any other income the property produces.

  2. Take off vacancy. Deduct your expected empty period. Even a well-run rental turns over eventually.

  3. Subtract operating expenses. Everything it costs to run the property, excluding the mortgage.

  4. Divide by the price. That gives the cap rate. Compare it against other properties in the same market, not against a national figure.

See a worked example: a $400,000 property renting at $2,500 a month
Price
$400,000
Gross rent
$30,000 a year
Operating expenses
40% of rent

Gross annual rent: $2,500 × 12 = $30,000.

Operating expenses at 40%: $12,000.

NOI: $30,000 − $12,000 = $18,000.

Cap rate: $18,000 ÷ $400,000 = 4.5%.

Working backwards, if similar properties trade at a 5% cap, that same $18,000 NOI implies a value of $360,000.

4.5% cap rate

Frequently asked questions

Problems people actually run into

Leaving the mortgage in the expenses

Deducting the loan payment from income produces something that looks like a cap rate and is not one. It makes a leveraged property look far worse than a cash purchase of the identical building, which is nonsense — it is the same building.

Keep financing out entirely. That is the whole reason the metric exists.

Assuming no vacancy and no management fee

A pro forma with 100% occupancy and no management cost is a fantasy, and it is exactly how deals get sold. Even a good rental sits empty between tenants, and self-managing is unpaid labour rather than a saving.

Building in 5-8% vacancy and 8-10% management typically knocks a full point off the headline cap rate, which is often the difference between a deal working and not.

Results are estimates for general information only and are not professional financial, medical, or legal advice. Read our full disclaimer.

Last updated: September 4, 2026