What is Cap Rate? How to Use It to Evaluate Any Rental Property

Cap rate is the single most-used metric in commercial and residential real estate investment. It tells you, in one number, how much annual return a property generates relative to its price — without the noise of financing. If you invest in rental properties, understanding cap rate is non-negotiable.

  • Cap Rate = NOI / Property Value — measures income return ignoring financing
  • Good cap rates vary by market: 4–5% is typical in prime cities, 7–9% in secondary markets
  • Cap rate ignores debt — always model cash-on-cash return to see actual leveraged returns
  • Best used for comparing properties in the same market and asset class
  • Low cap rate = more expensive, less income, more appreciation expected
  • Commercial property value can be estimated directly: Value = NOI / Market Cap Rate

The cap rate formula

Cap Rate = Net Operating Income (NOI) / Property Value × 100

NOI is the property's annual gross rental income minus all operating expenses (property management, insurance, taxes, maintenance, vacancy allowance). It does NOT include mortgage payments.

Example: A property worth $300,000 generates $24,000/year in rent and has $6,000 in operating expenses. NOI = $18,000. Cap Rate = 18,000 / 300,000 × 100 = 6%.

What is a "good" cap rate?

There is no universal answer — it depends entirely on location, asset class, and market conditions. As a general benchmark in the US:

3–4%: Prime urban markets (Manhattan, San Francisco). Low risk, low return, high appreciation expected.
5–6%: Mid-tier cities, stable suburban markets. Balanced risk/return.
7–9%: Secondary cities, higher-vacancy risk markets. Higher yield but more active management.
10%+: High-yield markets (Midwest, some Sun Belt cities). Often higher risk or distressed assets.

Low cap rates signal that investors are paying a premium for stability and appreciation. High cap rates signal higher income but potentially more risk.

Cap rate vs cash-on-cash return: the key difference

Cap rate ignores how you financed the property. Cash-on-cash return measures the actual cash return on the cash you invested (including the effect of your mortgage).

Example: You buy a $300,000 property (cap rate 6%, NOI $18,000) with a $240,000 mortgage at 7% (annual payment ~$19,200). After mortgage: $18,000 - $19,200 = -$1,200/year. Cash-on-cash return on your $60,000 down payment = -2%.

This is why cap rate alone is not enough — you must model the full financing picture to understand actual returns.

Using cap rate to compare properties

Cap rate's real power is as a comparison tool. Instead of comparing purchase prices (which are meaningless without context), you compare cap rates.

If two identical properties in the same neighborhood have different cap rates — say 5.5% vs 6.5% — the higher cap rate property is generating more income per dollar of value. Either the lower-cap property is overpriced, or the higher-cap one is underpriced. Cap rate quickly surfaces these discrepancies.

It also allows you to compare across different property types: a residential rental at 5% vs a small commercial building at 7% — you can assess the risk-adjusted tradeoff immediately.

When cap rate does NOT work

Cap rate is a poor metric for:

  1. Properties you intend to flip (no stable NOI).
  2. Highly leveraged deals (financing cost dominates returns).
  3. Properties with unstable income (short-term rentals, turnaround assets).
  4. Land or development projects.

Also, cap rate is a snapshot — it uses current income and current price. If you expect rents to rise 20% or the neighborhood to gentrify, the future cap rate will look very different. Always project forward, not just backward.

Cap rate and property valuation

Cap rate runs in reverse for commercial property valuation. If you know the NOI and the prevailing cap rate for comparable properties in that market, you can estimate value: Property Value = NOI / Cap Rate.

If a commercial building generates $50,000 NOI and market cap rates are 6%, the estimated value = $50,000 / 0.06 = $833,333. This is the income approach to valuation — used by appraisers and institutional buyers.

For residential real estate, this method is less common (comparables dominate), but it is still useful as a sanity check on asking prices.

Frequently asked questions

What is cap rate?

NOI divided by the property's value or price: the return it would give if bought in cash.

What is a good cap rate?

It depends on location and risk. Prime areas have lower cap rates; riskier areas, higher ones.

Cap rate or cash-on-cash?

Cap rate ignores financing and compares properties. Cash-on-cash measures the return on your own cash, including the mortgage.

When is cap rate not useful?

For properties with unstable income, heavy renovation or when appreciation is the main driver.

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