I have watched a lot of people fall in love with a property because of one number. Usually it is the cap rate, because it is the number that gets printed on the flyer. They repeat it like a password. Seven cap. Eight cap. As if the size of that single figure settles the whole question of whether the deal is any good.
It does not. And the gap between what people think the cap rate tells them and what it actually tells them is one of the most expensive misunderstandings in this business. So let me walk through both cap rate and cash-on-cash return the way I wish someone had walked me through them years ago, back when I was still treating a spreadsheet like a crystal ball.
This is a teaching piece, not a recommendation on any specific property. Please read the note near the end about advice.
What a cap rate actually measures
Cap rate is short for capitalization rate, and the formula is simpler than the name suggests.
Cap rate equals net operating income divided by price.
Net operating income, or NOI, is the money the property produces after operating expenses but before your mortgage. So you take your gross rents, subtract vacancy, property taxes, insurance, management, repairs, utilities you cover, and reserves, and what is left is NOI. You do not subtract the loan payment. That is the part people forget.
Here is why that matters. Cap rate is deliberately financing independent. It asks a clean question. If I paid all cash for this building, with no loan at all, what unlevered return would the property throw off in year one relative to what I paid for it. That is it. It describes the asset, not your deal on the asset.
So when a broker tells you a property is a seven cap, they are telling you that the NOI is seven percent of the asking price. It is a way of comparing buildings to each other on equal footing, stripped of whatever creative financing anyone might layer on top. Lower cap rates generally mean the market considers the asset safer or more desirable, which is why prime buildings in strong markets trade at low caps and tired buildings in thin markets trade at high ones. A high cap rate is not a prize. It is often the market pricing in risk.
What cash-on-cash return actually measures
Cash-on-cash return answers a completely different question, and it is the one that lands in your bank account.
Cash-on-cash equals annual pre-tax cash flow divided by total cash invested.
Annual pre-tax cash flow is what is left after you pay the mortgage. So it is NOI minus debt service. Total cash invested is the actual money that left your pocket to get into the deal. Down payment, closing costs, and any money you spent up front to make the property rentable.
Where cap rate ignores your loan entirely, cash-on-cash is built around it. It measures how hard the specific dollars you put in are working for you, given exactly how you financed the purchase. Change your down payment, change your interest rate, change your closing costs, and the cash-on-cash number moves. The cap rate does not budge, because the building did not change. Only your deal did.
That difference is the whole point, and it is why arguing about which number is better misses the mark. They are answering two different questions. One describes the property. The other describes your position in it.
Why cap rate alone will mislead you
Here is the trap. A cap rate looks like a return, so people treat it like their return. It is not. Almost nobody buys with all cash, which means almost nobody actually earns the cap rate. The moment you put a loan on a property, your real return diverges from the cap rate, sometimes dramatically in your favor and sometimes brutally against you.
When your interest rate is below the cap rate, leverage works for you. You borrow money at a cost lower than what the building yields, and the spread flows to your equity. This is positive leverage, and it is how a seven cap property can hand you a double digit cash-on-cash return.
When your interest rate is above the cap rate, leverage works against you. You are borrowing at a cost higher than the building yields, and that gap eats into the cash you put in. This is negative leverage, and it is exactly the situation a lot of buyers walked straight into during the years when rates climbed faster than prices adjusted. They saw a respectable cap rate, assumed the deal was fine, and only discovered after closing that their actual cash flow was thin or negative.
So the cap rate is real and useful, but it is describing a version of the deal that most of us never live in. Treating it as your return is like judging a car by its top speed when you only ever drive in traffic.
How financing rewrites the picture
Let me make the leverage point concrete before the full example, because this is where the two numbers pull apart.
Say a property has a fixed NOI. That NOI is a fact about the building and its rents, and the cap rate flows straight from it and the price. Now imagine three buyers.
The first pays all cash. Her cash-on-cash return will land right around the cap rate, because she has no loan to change the math.
The second borrows at a rate below the cap rate. His debt service is cheaper than what the building earns, so the leftover cash flow, spread across a much smaller amount of invested equity, produces a cash-on-cash return higher than the cap rate.
The third borrows at a rate above the cap rate. Her debt service is more expensive than what the building earns, so even though the cap rate looks identical to the second buyer’s, her cash-on-cash return comes out lower, maybe painfully so.
Same building. Same cap rate. Three completely different outcomes for the humans involved. That is why I never let anyone hand me a cap rate and call it a day.
Two quick screens: DSCR and the 1 percent rule
Before I run the full numbers on anything, I use two fast filters to decide whether a deal is even worth my afternoon.
The first is DSCR, or debt service coverage ratio. It is NOI divided by annual debt service. It tells you how comfortably the property’s income covers its loan. A DSCR of 1.0 means the income exactly covers the payment with nothing to spare, which is a knife’s edge. Lenders usually want to see something like 1.2 or 1.25 before they are comfortable, and honestly, so do I, because that cushion is what absorbs a surprise vacancy or a broken furnace without me feeding the property from my own pocket.
The second is the 1 percent rule. It is a rough screen that asks whether the monthly rent is at least one percent of the purchase price. It is not gospel. In expensive coastal markets almost nothing clears it, and plenty of good deals sit just under it. But as a first glance, it quickly separates properties that might cash flow from properties that almost certainly will not. I treat it as a smoke alarm, not a verdict.
Neither of these replaces real underwriting. They just keep me from wasting hours on deals that were never going to work.
A worked example, clearly hypothetical
Let me run one property through both numbers so you can watch them separate. Every figure here is invented for teaching. It is not a real listing and not a promise about any market.
Imagine a small multifamily building listed at $450,000.
Start with the income side. Gross scheduled rent comes to $54,000 a year. I knock off five percent for vacancy and credit loss, which is $2,700, leaving effective gross income of $51,300.
Now operating expenses. Property taxes of $5,400. Insurance of $2,400. Property management at eight percent of collected rent, roughly $4,100. Repairs and maintenance of $3,600. Reserves for the big future items of $2,400. That is $17,900 in operating expenses. I am not counting the mortgage here, on purpose, because the mortgage is not an operating expense.
So NOI is $51,300 minus $17,900, which is $33,400.
The cap rate falls right out of that. NOI of $33,400 divided by the price of $450,000 gives a cap rate of about 7.4 percent. On the flyer, this is a seven and a half cap building. Clean, respectable, nothing exotic.
Now let us actually buy it, because I am not paying all cash.
I put twenty five percent down, which is $112,500. Closing costs and a little initial work run me another $15,000. So my total cash invested is $127,500.
I finance the remaining $337,500. At a fixed rate around seven percent on a thirty year amortization, the annual debt service comes to roughly $26,940.
Check the DSCR first. NOI of $33,400 divided by debt service of $26,940 gives a DSCR of about 1.24. That clears my comfort line, barely. The building covers its loan with a modest cushion.
Now the number that actually hits my account. Annual pre-tax cash flow is NOI minus debt service, so $33,400 minus $26,940, which is $6,460.
Cash-on-cash return is that cash flow divided by my cash invested. So $6,460 divided by $127,500 gives about 5.1 percent.
Sit with that for a second. The flyer said 7.4 percent. My actual cash-on-cash return on the dollars I risked is 5.1 percent. Nothing was fraudulent. Both numbers are correct. They are simply answering different questions, and my seven percent loan cost, sitting just below the cap rate, is thin enough that positive leverage barely helped me. The building earns 7.4 percent unlevered, my money earns 5.1 percent levered, and the gap is the story.
Now flip one variable to see how alive these numbers are. Suppose I could borrow at five percent instead of seven. Annual debt service drops to roughly $21,750. Cash flow becomes $33,400 minus $21,750, which is $11,650. Cash-on-cash jumps to about 9.1 percent on the same $127,500. The building did not change. The cap rate is still 7.4 percent. Only my financing changed, and my personal return nearly doubled. That is leverage doing its quiet, powerful work in the direction you want.
How I actually decide
So which number matters. My honest answer is that they both do, and I use them in a sequence.
The cap rate is my first read on the asset. It tells me how the market prices this building against others like it, and whether the price is even in the neighborhood of sane. If the cap rate is wildly out of step with comparable properties, that is a question I need answered before I go further, in either direction.
Then cash-on-cash tells me whether my deal, with my money and my financing, actually works. This is the number I live with month to month. It is where DSCR sits alongside it as a safety check, because a great cash-on-cash return with a DSCR hovering near 1.0 is a return that will vanish the first month a unit sits empty.
I care about the spread between the cap rate and my borrowing cost, because that spread tells me whether leverage is my friend or my enemy on this particular deal. I care about the DSCR, because it tells me whether I can sleep at night. And I never, ever let a single headline number make the decision for me, because the headline number is designed to be attractive, not complete.
The investors I watch get into trouble are almost always the ones who anchored on one figure and stopped asking questions. The number was not lying to them. They just did not know which question it was answering.
If you want to run these numbers on a property you are looking at, I built a free calculator that walks through cap rate, cash-on-cash, and DSCR together so you can see all three move at once. Watching them shift as you change the down payment or the rate teaches the lesson faster than any article can.
A necessary and honest note. This is educational, not financial or investment advice. I do not know your situation, your market, your tax picture, or your risk tolerance, and every number in that example was invented to illustrate the math. Run your own underwriting and bring in professionals who can look at your actual deal.
If this way of thinking is useful to you, I share more of it in my Operator’s Notes newsletter, where I write through the real decisions as I make them, without the polish. And I go deeper on this kind of thing with guests on The Broker’s Table podcast, where working operators talk honestly about the numbers behind their deals. Come sit at the table. There is always room for one more.
