Cap Rate Explained for Property Investors

The capitalization rate — cap rate for short — is the property world's version of a yield on an income asset. It tells you the annual return a property produces relative to its price, before any financing, so you can compare very different deals on equal terms.

The formula

The key term is net operating income (NOI): the rent a property collects in a year minus its operating expenses. Crucially, NOI excludes financing payments and income tax — that's what makes the cap rate financing-neutral.

What goes into net operating income

Start with gross rental income, then subtract the costs of running the property:

• Property management and letting fees
• Insurance
• Repairs and maintenance
• Service charges, ground rent or HOA fees
• An allowance for vacancy (void periods)

Do not subtract financing costs or income tax — those depend on the buyer, not the building. The cap rate calculator handles the arithmetic once you've gathered these figures.

Reading the number

A higher cap rate means more income relative to price — but it usually also signals more risk, whether that's a weaker location, shorter leases or more management. A lower cap rate typically reflects a safer, more sought-after asset where buyers accept less income for more stability and growth potential.

Cap rate vs rental yield

The two are almost the same idea. Net rental yield and cap rate both divide income-after-costs by value. In practice, "cap rate" is the term used for commercial and larger income properties, while "rental yield" is more common for residential buy-to-let. If you calculate net yield correctly, you've essentially calculated the cap rate.

One limitation to keep in mind: a single year's cap rate is a snapshot. It doesn't capture rent growth, future capital expenditure or changes in the area. Use it to shortlist and compare, then dig deeper on the properties that pass the screen.