Cap Rate vs Cash-on-Cash Return

Two investors look at the same fourplex. One says the cap rate is 6% and passes. The other says the cash-on-cash return is 11% and buys. Neither is wrong — they're measuring different things, and the gap between their answers is the whole point of understanding both.

The difference in one line

Cap rate ignores your mortgage. Cash-on-cash return is mostly about your mortgage.

That's really it. Everything else is detail.

Cap rate: what the property earns on its own

Cap rate asks a simple question: if you paid all cash, what would this property yield? You take the net operating income — rent minus every operating expense, but not the mortgage — and divide by the price.

Cap rate = net operating income ÷ price.

A property with $18,000 of NOI and a $300,000 price has a 6% cap rate. Because the mortgage never enters the math, the cap rate is a property of the building and its market, not of your financing. Two buyers get the same cap rate on the same property even if one pays cash and the other borrows 80%. That's exactly what makes it useful for comparing deals — it's a clean, finance-free yardstick, which is why appraisers lean on it to value income property.

Cash-on-cash: what your money earns

Cash-on-cash return asks a more personal question: of the actual dollars I put into this deal, what percentage comes back to me each year?

Cash-on-cash = annual pre-tax cash flow ÷ total cash invested.

Now the mortgage matters enormously, because "cash flow" is what's left after the loan payment, and "cash invested" is your down payment plus closing costs and any rehab — not the full price. This number is about your position in the deal, not the building's.

Same property, two numbers

Take that $300,000 fourplex with $18,000 of NOI. The cap rate is 6%, full stop, no matter how you buy it.

Paying cash. You put in $300,000 and pocket the full $18,000 (there's no mortgage eating into it). Cash-on-cash is $18,000 ÷ $300,000 = 6% — the same as the cap rate. With no loan, the two metrics collapse into one.

Putting 25% down. Now you invest $75,000 plus, say, $10,000 in closing costs — $85,000 in. But the mortgage on the other $225,000 costs you roughly $16,800 a year, so your cash flow drops to about $1,200. Cash-on-cash is $1,200 ÷ $85,000 ≈ 1.4%.

Same building, same 6% cap rate, and the cash-on-cash swings from 6% to 1.4% purely on financing. Borrow at a rate below the cap rate and leverage lifts your return; borrow above it — which is common right now, with rates high — and leverage drags it down. That's the tension every financed deal lives inside.

Which one should you actually use?

Both. They answer different questions, and using one alone is how people talk themselves into bad deals.

Reach for cap rate when you're comparing properties, sizing up a market, or estimating what an income property is worth. It strips out the noise of who's financing what and lets you line up a duplex against a fourplex fairly. Appraisers and commercial investors basically run on it. You can even flip the formula around — decide the return you need, and a reverse cap rate tells you the most you should pay for a given income stream.

Reach for cash-on-cash when you've got a specific deal with specific financing and you want to know what your money will do. It's the number that reflects your actual return, and it's what you compare against alternatives — an index fund, a different property, paying down other debt.

If you only remember one thing: a strong cap rate with weak cash-on-cash usually means expensive financing, and thin cash-on-cash isn't automatically a bad deal if appreciation is part of your thesis. Run both on any property you're serious about — the rental calculator gives you cash flow and cash-on-cash with a mortgage attached, and the cap rate calculator handles the unlevered side.

Frequently asked questions

What's the difference between cap rate and cash-on-cash return?

Cap rate is net operating income divided by price and ignores financing — it measures the property's unleveraged yield. Cash-on-cash return is annual cash flow divided by the cash you actually invested, so your mortgage and down payment drive it. They match only when you pay all cash.

Is a higher cap rate or cash-on-cash return better?

Higher is generally better for both, but context matters. A high cap rate often signals higher risk or a weaker market, and cash-on-cash depends heavily on your financing terms. Compare properties on cap rate, then evaluate your specific deal on cash-on-cash.

Why is my cash-on-cash return lower than the cap rate?

Because your mortgage costs more than the property yields. When your loan's interest rate is above the cap rate, leverage reduces your return rather than boosting it — common in a high-rate market. Paying all cash makes the two metrics equal.

Which metric do appraisers use?

Cap rate. Because it's independent of financing, it lets appraisers and commercial investors value an income stream and compare properties on equal footing. Cash-on-cash is an investor's personal-return metric, not a valuation tool.