What is yield on cost?

Yield on cost is stabilized net operating income divided by total development cost. It answers what a project earns on every dollar put into it once the building is finished and leased. Unlike a cap rate, which prices a building someone else already built, yield on cost measures what you create by building it.

What is the development spread and how much do I need?

The development spread is yield on cost minus the market exit cap rate for the finished asset. It is the compensation for taking construction, lease-up and timing risk. Sponsors and lenders commonly look for a spread in the range of 100 to 200 basis points, and the required spread widens when construction timelines stretch, when rates are volatile, or when a lot of competing supply is delivering into the same submarket. Underwrite the spread your own capital requires rather than a rule of thumb.

Does the operating expense ratio include real estate taxes and insurance?

It should, and in most markets those two lines are what move it. Include taxes, insurance, payroll, repairs and maintenance, utilities, marketing, management fee, and a replacement reserve if your lender sizes to one. In South Florida the insurance line alone has pushed expense ratios materially above the historical norm, so a ratio carried over from an older deal will understate the rent you need.

Is this rent number gross rent or net rent?

The calculator solves for the effective revenue per unit per month, meaning what is actually collected after vacancy, concessions and credit loss. If your rent roll or comparable set quotes asking rents, gross the result back up by your vacancy and concession assumptions before comparing. Skipping that step is the most common reason a deal looks like it pencils when it does not.

TOOLS / UNDERWRITING

Yield on cost, and the rent to pencil

Every development eventually reduces to one question: what does this have to rent for. Enter the cost, the unit count, the yield your capital requires and your expense ratio, and this solves backwards to the rent.

Reviewed Jul 18, 2026 · The American Developer

Result

Required rent, per unit per month

$2,885

Effective revenue per unit per month at stabilization, meaning after vacancy, concessions and credit loss. Gross it back up before comparing to asking rents.

Implied stabilized NOI, annual

$2,700,000

The net operating income the project must produce to hit the target yield on its total cost.

Cost per unit

$375,000

NOI per unit, annual

$22,500

Required gross income, annual

$4,153,846

Operating expenses, annual

$1,453,846

The formula

required NOI = total development cost × yield on cost

required effective gross income = required NOI ÷ (1 − operating expense ratio)

required monthly rent per unit = required effective gross income ÷ unit count ÷ 12

Worked with the defaults on this page: $45,000,000 × 6.0% = $2,700,000 of NOI. Divided by (1 − 0.35) that is $4,153,846 of effective gross income, or $2,884.62 per unit per month across 120 units. Expenses are the difference, $1,453,846 a year.

One assumption is doing real work here: the expense ratio is applied to effective gross income, so the rent this returns is collected revenue per unit, not an asking rent. If your comparable set quotes asking rents at a 5 percent vacancy and one month free, the asking rent you need is meaningfully higher than the number above.

What the number means

Yield on cost is the return the building throws off relative to what it cost to create, measured once it is finished and leased. It is the development equivalent of a cap rate, with one crucial difference: a cap rate prices an asset the market has already valued, while yield on cost measures value you are creating from scratch. The gap between the two is the entire economic case for building instead of buying.

That gap has a name, the development spread. If comparable stabilized assets trade at a 5.0 cap and your project pencils to a 6.5 yield on cost, you are creating 150 basis points of value for taking construction risk, lease-up risk and roughly three years of interest-rate risk. When the spread compresses toward zero, the rational move is to buy the finished building rather than build a new one, which is exactly what stalls development pipelines.

How professionals use it

Developers run it backwards, as this tool does. The cost is largely known and the required yield is set by capital, so the output is the rent the market has to support. If that rent is above the top of the comparable set, the deal does not work no matter how good the site is.
Construction companies and builders use it to understand why a client is value-engineering. A 5 percent hard-cost increase does not shave 5 percent off the developer's margin, it raises the required rent, and the rent is set by the market and not by the budget.
Agents and brokers use it to sanity-check a land price before bringing a site to a developer, and to explain to a seller why a bid came in where it did.
Lenders and equity use the spread to size the deal and to decide whether the sponsor's rent assumptions are underwriting or hoping.

Where it misleads

The expense ratio is the quiet killer. Carrying a 30 percent ratio from a deal underwritten a few years ago into a South Florida project today can understate the required rent by hundreds of dollars a unit, because insurance and taxes have not moved in line with everything else. Two other cautions: total development cost has to be genuinely all in, including financing costs and contingency, or the yield is flattered by omission; and a single blended rent across a mixed unit mix hides the fact that the studios and the three-bedrooms have to clear very different numbers. Run the mix separately once this tool tells you the blended target.

Finally, this is a stabilized snapshot. It says nothing about how long lease-up takes, what the construction loan costs while you get there, or what happens if delivery lands in the same quarter as three competing projects. Yield on cost is the screen, not the model.

Frequently asked

What is yield on cost?: Yield on cost is stabilized net operating income divided by total development cost. It answers what a project earns on every dollar put into it once the building is finished and leased. Unlike a cap rate, which prices a building someone else already built, yield on cost measures what you create by building it.
What is the development spread and how much do I need?: The development spread is yield on cost minus the market exit cap rate for the finished asset. It is the compensation for taking construction, lease-up and timing risk. Sponsors and lenders commonly look for a spread in the range of 100 to 200 basis points, and the required spread widens when construction timelines stretch, when rates are volatile, or when a lot of competing supply is delivering into the same submarket. Underwrite the spread your own capital requires rather than a rule of thumb.
Does the operating expense ratio include real estate taxes and insurance?: It should, and in most markets those two lines are what move it. Include taxes, insurance, payroll, repairs and maintenance, utilities, marketing, management fee, and a replacement reserve if your lender sizes to one. In South Florida the insurance line alone has pushed expense ratios materially above the historical norm, so a ratio carried over from an older deal will understate the rent you need.
Is this rent number gross rent or net rent?: The calculator solves for the effective revenue per unit per month, meaning what is actually collected after vacancy, concessions and credit loss. If your rent roll or comparable set quotes asking rents, gross the result back up by your vacancy and concession assumptions before comparing. Skipping that step is the most common reason a deal looks like it pencils when it does not.