Cash on Cash Return and Leverage: When Borrowing Helps and When It Hurts

Borrowing raises your cash on cash return only when the loan costs less per year than the property earns per year. That single comparison decides whether more leverage means more return or less.

The comparison is not interest rate versus cap rate, though that is how it is usually stated. It is the mortgage constant versus cap rate, and at today’s rates the difference matters.

The comparison that decides it

The mortgage constant is a year of payments divided by the loan balance. On an amortizing loan it includes principal, so it runs above the interest rate. Some figures for a 30-year loan:

Interest rate	Mortgage constant
4.0%	5.7%
5.0%	6.4%
6.0%	7.2%
7.0%	8.0%
7.25%	8.2%
8.0%	8.8%

Cap rate is net operating income divided by price, the yield the property pays before any loan.

If cap rate is higher than the constant, borrowed dollars earn more than they cost. The return on your cash rises as you borrow more. That is positive leverage.

If cap rate is lower than the constant, borrowed dollars cost more than they earn. The return on your cash falls as you borrow more. That is negative leverage.

Watching it flip

A $250,000 rental with $20,105 of net operating income. Cap rate 8.0%.

At a 5% rate the constant is 6.4%, below the cap rate. Leverage is positive:

• All cash: 7.7% cash on cash
• 25% down: 10.7%
• 20% down: 11.5%

At a 7.25% rate the constant is 8.2%, just above the cap rate. Leverage is negative:

• All cash: 7.7%
• 25% down: 6.3%
• 20% down: 6.0%

Same property, same rent, same expenses. In one case borrowing more pushes the return up. In the other it pushes it down. The only thing that changed was the cost of the loan.

This is why the investing advice of the 2010s, when rates were 4% and cap rates were 6 to 8%, said to put down as little as possible. The constant was well below the cap rate almost everywhere. At 7% and up, that advice is wrong for most properties in most markets.

Why the all-cash return is the reference

The calculator shows an all-cash return next to the financed one. It is the cash on cash return you would earn with no loan: net operating income divided by price plus closing costs and repairs. It sits just under the cap rate because of those closing costs.

If your financed return is above the all-cash return, leverage is working for you. If it is below, leverage is working against you, and the question becomes whether the other benefits of borrowing justify the drag.

Why investors borrow anyway

Negative leverage on a cash on cash basis is not automatically a mistake. Three reasons investors accept it:

Capital efficiency. $75,000 in one property at 6.3% or $262,500 in one property at 7.7%. The financed investor has $187,500 left for other deals. Three financed properties at 6.3% produce more total cash flow than one all-cash property at 7.7%, and three times the appreciation and paydown exposure.

Total return. Leverage magnifies appreciation and adds principal paydown. A property appreciating 3% adds $7,500 to the value whether you own it with $75,000 or $262,500 of cash. On $75,000 that is 10 points of return. On $262,500 it is under 3. The cash on cash vs ROI guide works this through.

Refinance optionality. An investor who buys at 7.25% with negative leverage and refinances at 5.5% two years later flips to positive leverage on the same property. The cash on cash return in year one was the price of getting in.

None of those reasons changes the arithmetic. They are reasons to accept a lower cash yield knowingly.

How to decide how much to put down

Run the deal at 20%, 25%, 30% and all cash in the calculator. If the return rises as you put more down, leverage is negative at this rate and cap rate. Then ask three questions:

How much cash yield do you need? If you need the property to cover itself with room to spare, more down is safer when leverage is negative. If you can carry a thin margin, less down preserves capital.

What else would the cash do? If the next deal is a 9% return, tying an extra $12,500 into this one at 6% has a cost. If there is no next deal, the extra down payment is earning the marginal return of the debt it replaces, about 8.2% at 7.25%, which is not bad.

Will the rate change? If a refinance is likely, the down payment decision is temporary. If the loan is fixed for the hold, it is permanent.

Interest-only and leverage

An interest-only payment removes principal from the constant. At 7.25%, the constant drops from 8.2% to 7.25%, which is below an 8.0% cap rate. Leverage flips from slightly negative to slightly positive, and the example’s cash on cash return rises from 6.3% to 8.7%.

The reset is the catch. When the interest-only period ends, the constant jumps above where an ordinary 30-year loan would have been, because the balance now amortizes over fewer years. Interest-only creates positive leverage on a timer. Know when the timer ends before you count on it.

The one-line check

Compare the mortgage constant to the cap rate. Above it, borrow more. Below it, borrow less, or have a reason. The calculator shows the all-cash return beside the financed return on every run, so the direction of leverage is visible without any extra math. The how to increase cash on cash return guide covers the other eight levers.