Cap rate versus cash on cash return
How the cap rate and cash on cash return differ, when each metric is useful, and how financing changes the return on a rental.
Two questions, two metrics
Cap rate and cash on cash return both describe how well a rental performs, but they answer different questions. Cap rate asks what the property yields on its full price with no loan, using net operating income over value. Cash on cash return asks what your actual invested cash earns after the mortgage is paid, using annual pre tax cash flow over the money you put in. Because they measure different denominators, the same property can show a modest cap rate yet a much larger cash on cash figure once leverage is added.
Why financing splits the two
This calculator focuses on cap rate precisely because it removes financing from the comparison. Net operating income stops before the mortgage line, so two investors buying the identical building compute the identical cap rate. The moment a loan enters, monthly principal and interest reduce the cash that actually reaches your pocket, and the size of your down payment changes the cash you invested. Those two shifts are what cash on cash captures and cap rate ignores, which is why you should look at both before committing.
Using cap rate to compare deals
Cap rate shines as a quick screening tool across a market. If similar buildings in an area trade around a 6 percent cap rate, a listing priced at a 4 percent cap looks expensive and one at 8 percent deserves a closer look for hidden problems. You can also run the calculator in reverse: fix a target cap rate that reflects local norms, plug in the NOI, and read the price you should be willing to pay. That turns a subjective negotiation into a number you can defend.
Limits worth remembering
A cap rate is only as honest as the NOI behind it, so pad your expense estimates with realistic figures for vacancy, repairs and management even if you self manage. It is a snapshot of one year and says nothing about rent growth, appreciation or the tax treatment of the asset. For a fuller picture, pair the cap rate with a cash on cash return and a longer term return on investment estimate. Treat the output here as a clean starting benchmark rather than the final word on a deal.