Yield-on-cost is the net operating income (or sometimes cash flow from operations) at stabilization divided by the total project cost, whereas the capitalization rate (cap rate) is the stabilized net operating income (or sometimes cash flow from operations) divided by the market value of the property.

Net Operating Income at Stabilization ÷ Project Cost

The yield-on-cost serves to help the real estate investor calculate the difference between the market yield and the actual yield of an investment. In development, this difference between market yield (market cap rate) and actual yield (yield-on-cost) is called the development spread.