Real Estate NOI and Cap Rate Analysis

Real estate investment analysis comes down to two numbers: Net Operating Income (NOI) and Cap Rate. Everything else — cash-on-cash return, equity multiple, IRR — is built on top of these two. If you understand them, you can evaluate any income-producing property.

Net Operating Income

NOI is the annual income generated by a property after operating expenses but before debt service and income taxes. The formula is straightforward: NOI = Gross Rental Income - Vacancy and Credit Loss - Operating Expenses.

Gross rental income is the total rent you'd collect if every unit were occupied at market rate for the full year. Vacancy and credit loss is a deduction for the units that will be empty or where tenants won't pay — typically modeled as a percentage of gross income. Five percent is a common assumption for stabilized properties in strong markets; 10–15% is more appropriate for value-add properties or weaker markets.

Operating expenses include property taxes, insurance, property management fees, maintenance and repairs, utilities (if paid by the owner), and reserves for capital expenditures. What's not included in NOI: mortgage payments, depreciation, and income taxes. NOI is a pre-financing, pre-tax metric.

Cap Rate

The capitalization rate (cap rate) is the ratio of a property's NOI to its market value. Cap Rate = NOI / Property Value. If a property generates $100,000 in NOI and is worth $1,250,000, the cap rate is 8%.

Cap rate serves two purposes. First, it's a valuation tool: if you know the NOI and the prevailing cap rate for comparable properties in the market, you can estimate the property's value. Value = NOI / Cap Rate. Second, it's a return metric: the cap rate represents your unlevered return on the property — what you'd earn if you paid all cash with no mortgage.

What drives cap rates

Cap rates vary by property type, location, and market conditions. Class A multifamily properties in major metros might trade at 4–5% cap rates. Class B industrial properties in secondary markets might trade at 6–8%. Retail and office properties have seen cap rate compression in some markets and expansion in others depending on demand trends.

Lower cap rates mean higher valuations relative to income — investors are paying more for each dollar of NOI. This typically reflects lower perceived risk, stronger rent growth expectations, or both. Higher cap rates mean lower valuations relative to income, reflecting higher risk or weaker growth expectations.

Using NOI and cap rate in your model

When you're underwriting an acquisition, model the NOI conservatively. Use market rents, not optimistic projections. Use a vacancy rate that reflects the property's current condition and the local market, not a stabilized assumption you haven't earned yet. Use actual operating expenses from the seller's records, adjusted for any items you know will change under your ownership.

Then apply the prevailing cap rate for comparable properties to get your estimate of stabilized value. Compare that to your acquisition price plus renovation costs to assess whether the deal makes sense.

Horizon's Real Estate model tracks NOI and cap rate at the property level, with inputs for unit count, average rent, vacancy rate, and operating expense categories. The model shows you how your NOI and implied value change as you adjust your assumptions — useful for both underwriting new acquisitions and tracking the performance of existing properties.