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Cap Rate Calculator for Rental Properties

Estimate net operating income and unlevered yield from purchase price, rent, vacancy, and operating expense assumptions—then see which inputs are doing the work.

Written by InvestUSCAReviewed by InvestUSCA editorUpdated September 12, 2026

INPUTS

Make the assumptions explicit.

Acquisition & income

Annual operating expenses

Enter annual expenses as dollar amounts. If an expense is already included in your management or HOA assumption, do not enter it twice.

LIVE OUTPUT

Unlevered property screen

No account required

Estimated cap rate

5.08%

NOI ÷ purchase price. Financing is not included.

Net operating income

$25,380

Effective gross income

$39,900

Operating expenses

$14,520

Gross rent yield

8.4%

Operating expense ratio

36.39%

Operating break-even occupancy

34.57%

Gross potential income: $42,000

Vacancy & credit loss: $2,100

A cap rate is a screening metric. It is not a promised return and does not include debt service, closing costs, income taxes, depreciation, appreciation, or selling costs.

THE FORMULA

Simple math. Visible assumptions.

Effective gross income = gross potential income − vacancy loss

NOI = effective gross income − operating expenses

Cap rate = NOI ÷ purchase price

WHAT THIS TOOL IS FOR

A first screen before a full underwriting model

Use cap rate to compare unlevered property economics under a consistent set of assumptions. It helps you ask whether the asking price is supported by the property’s operating income, but it cannot tell you whether the property fits your financing, tax position, risk tolerance, or investment plan.

NOI
Gross yield
Operating break-even occupancy

LIMITATIONS

What the cap rate does not answer

Financing

Mortgage rate, leverage, amortization, and debt service belong in a cash-flow or cash-on-cash model.

Closing and selling costs

Transaction costs can change your basis and exit proceeds even when NOI stays unchanged.

Taxes and depreciation

Income-tax outcomes depend on the owner, entity, jurisdiction, and tax strategy.

Future performance

The calculator describes the assumptions entered; it does not forecast rent growth, appreciation, or vacancy.

CAP RATE FAQ

Questions investors usually ask next

What is a cap rate?

Cap rate is net operating income divided by the property purchase price. It is an unlevered screening metric, so this calculator does not include mortgage payments or other financing effects.

What expenses should be included in a cap rate calculation?

Include recurring operating expenses such as property tax, insurance, HOA, maintenance, management, utilities paid by the owner, and other operating costs. Keep mortgage principal and interest outside NOI.

Is cap rate the same as cash-on-cash return?

No. Cap rate compares NOI with the purchase price and ignores financing. Cash-on-cash return compares cash flow after financing with the cash invested, so the two metrics answer different questions.

Does a higher cap rate always mean a better investment?

No. A higher cap rate may reflect more operating, tenant, property-condition, market, or liquidity risk. Compare the assumptions, property quality, location, financing, and downside case before making a decision.

NEXT STEP

A cap rate is the beginning of the conversation.

Compare the screen with a market context page before you decide which property assumptions deserve deeper work.

Read the Boston market profile Run a full rental model