Is Cap Rate Gross or Net? Which Expenses Belong in the Calculation

Cap rate is net, not gross. The formula divides net operating income by price, and net operating income is rent after vacancy and after operating expenses: property taxes, insurance, maintenance, management. So yes, cap rate includes expenses, and yes, it includes property taxes. It does not include your mortgage payment, your income taxes or depreciation.

That line is where most beginner math goes wrong. Divide gross rent by price and a $500,000 house renting for $4,000 a month looks like a 9.6% property. Run the same house through its real operating costs and it earns 5.78%. Same house, same rent, two answers that are nowhere near each other.

Gross rent, then effective gross income, then NOI

Three income numbers sit between a rent roll and a cap rate. All three get called income, which is how the confusion starts.

Gross rent is the full rent with nothing taken out. At $4,000 a month, that is $48,000 a year.

Effective gross income is gross rent minus vacancy and uncollected rent. At 5% vacancy, $2,400 comes off, leaving $45,600. This is the money that actually reaches the bank account.

Net operating income is effective gross income minus operating expenses. On this property that means $6,000 of property taxes, $2,500 of insurance, and 18% of collected income, or $8,208, for maintenance, reserves and management. Expenses total $16,708, so NOI is $28,892.

The cap rate is the last step. $28,892 divided by $500,000 is 5.78%.

The gross version, $48,000 divided by $500,000, gives 9.6%. That is two thirds too high, and the gap is not a rounding issue. It is every cost of owning the house.

The expenses that belong in NOI

One test settles most arguments. If a cash buyer with no loan would still have to pay the bill every year to keep the place rented, it belongs in NOI.

That covers property taxes, property insurance, repairs and maintenance, property management, leasing and turnover costs, reserves for replacements, any utilities the owner pays, HOA dues, trash, landscaping, snow removal, pest control, licenses and inspections, and the bookkeeping for the property.

Manage the house yourself and the management fee still belongs in there. Your hours are a real cost, and the next owner may hire the job out. Market fees for single family rentals commonly run 8% to 10% of collected rent, with small multifamily and short term rentals higher, so check what local companies charge before you pick a number.

The costs that stay outside it

Mortgage principal and interest. Cap rate ignores debt on purpose. Two buyers paying $500,000 for the same house, one all cash and one with 20% down, both own a 5.78% property. Financing shows up in cash flow, not in the cap rate.

Income taxes. Your bracket is yours, not the building’s.

Depreciation and everything built on it. Depreciation is a tax entry, not a check you write. A cost segregation study can pull those deductions forward, and depreciation recapture can claw part of them back when you sell, but none of it touches NOI.

Acquisition costs. Closing costs, loan fees, inspections and the money you spend fixing the house up before the first tenant are all outside NOI. They belong in your basis and your total return, not in the yearly operating picture.

Where CapEx and reserves go

Capital expenditure is the item people argue about. A new roof, a new furnace, a gut kitchen: those are capital, and the actual spending stays out of NOI.

What goes in is the reserve, the yearly set aside for those items. A $12,000 roof that lasts 25 years is roughly $480 a year of real cost whether or not you wrote the check this year. Leave reserves out and NOI looks steady right up to the year the roof fails.

The 18% used here covers maintenance, reserves and management together. Underwriters often land somewhere between 15% and 25% of collected income for a single family house, depending on age, condition and whether management is hired out. Older house, bigger number.

Why a “gross cap rate” is not a cap rate

Gross rent divided by price already has a name. It is the inverse of the gross rent multiplier. This house is a 10.4 GRM, since $500,000 divided by $48,000 is 10.4. GRM is a decent first screen when you are sorting through listings fast, because rent and price are the only two inputs you need.

It is not a yield. It says nothing about taxes, insurance, condition or who pays the water bill. Call 9.6% a cap rate and you will treat a house in a 1% tax state and a house in a 3% tax state as if they earned the same money.

A fast audit of a seller’s expense list

Work down the statement and look for these:

• Vacancy at zero. Nobody keeps a house full forever. Put 5% back, more in a soft market.
• No management line. Add the market fee even if you plan to self manage.
• Taxes at the seller’s amount. Reassessment at your purchase price can move the bill, and exemptions the seller held may not transfer. Rules vary by state, so ask the assessor.
• Stale insurance. Premiums have moved a lot in storm and wildfire areas. Get your own quote.
• Maintenance missing or token. A $25 a month repair budget on a house is a placeholder, not a forecast.
• Mortgage interest or depreciation listed as expenses. Pull them out. They do not belong in NOI and they understate what the property earns.
• The expense ratio. This property spends $16,708 of $45,600, about 37% of collected income. A single family statement showing 15% is missing line items.

Here is what those gaps are worth. Suppose the seller keeps taxes at $6,000 and insurance at $2,500, charges 8% for maintenance only, and shows no vacancy, no management and no reserves. NOI comes to $35,660 on $48,000 of rent, which prices out at 7.13%. The honest version of the same house is 5.78%. That is 1.35 points of air, created entirely by lines left off a page.

Run it both ways

Cap Rate Calculator has two tabs for exactly this problem. The simple tab takes an NOI you already trust: put in $30,000 of NOI on a $500,000 price and it returns 6%. The detailed tab builds NOI from rent, vacancy, taxes, insurance and the operating percentage, which is how a $500,000 house at $4,000 a month lands on $28,892 and 5.78%. Use the detailed tab whenever the expense numbers came from a seller, and compare both figures on the cap rate calculator before you make an offer.