The Question Almost No One Asks
Most CRE investors run a deal through a calculator, see a cash-on-cash return, decide whether they like it, and move on. They never ask the deeper question: is leverage helping me or hurting me on this deal?
The answer is determined by one comparison: cap rate vs. loan constant.
The loan constant is your annual debt service divided by the loan amount. For amortizing loans, the loan constant always exceeds the stated interest rate because it includes principal repayment. A 6.75% interest rate on a 30-year amortizing loan produces a loan constant of roughly 7.78%.
If your cap rate is higher than your loan constant, you have positive leverage. Every dollar you borrow earns more than it costs.
If your cap rate is lower than your loan constant, you have negative leverage. Every dollar you borrow costs more than it earns.
Most investors compare cap rate to the interest rate. That comparison is wrong for amortizing loans and will overstate your leverage benefit. A 7% cap rate against a 6.75% interest rate looks positive. But 7% is less than the 7.78% loan constant. The deal is actually negatively levered.
This became dramatically more important after rates rose in 2022.
The Leverage Ratio: Why LTV Understates the Risk
Before the math, one concept institutional investors use that retail investors almost never do: the leverage ratio.
LTV tells you how much you borrowed. The leverage ratio tells you how much risk amplification you created.
| LTV | Leverage Ratio | What It Means |
|---|---|---|
| 0% | 1.0x | All equity. No amplification. |
| 50% | 2.0x | Risk doubled. |
| 60% | 2.5x | |
| 75% | 4.0x | Risk quadrupled. |
| 80% | 5.0x | A 20% decline wipes out your equity. |
The formula: Leverage Ratio = 1 / (1 - LTV). Going from 50% to 75% LTV sounds like a modest increase. In reality, you doubled the leverage ratio from 2x to 4x. The risk impact is far more severe than the LTV number suggests.
How Leverage Math Actually Works
Let's walk through two scenarios on a $1M building generating $60K NOI (6% cap rate). You put 30% down ($300K equity) and borrow $700K.
Scenario 1: 5% interest rate, interest-only (positive leverage)
- Annual debt service: $700K x 5% = $35K
- Loan constant: $35K / $700K = 5.0%
- Cap rate (6%) > loan constant (5%) = positive leverage
- Cash flow: $60K - $35K = $25K
- Cash-on-cash: $25K / $300K = 8.3%
The cap rate is 6%, but your equity earns 8.3%. The 1% spread between the cap rate and the loan constant, multiplied by the 2.33x leverage ratio, boosts the unlevered return by 2.3 percentage points.
Per Geltner's research at MIT, an important nuance: leverage does not increase the income return component. It leaves income yield unchanged. The entire return boost comes from appreciation magnification. In this example, if the property appreciates 2%, that 2% applies to $1M of property controlled by $300K of equity, so the appreciation return on equity is 6.7% rather than 2%.
Scenario 2: 7% interest rate, 30-year amortizing (negative leverage)
- Monthly payment on $700K at 7%/30yr: ~$4,657
- Annual debt service: ~$55,884
- Loan constant: $55,884 / $700K = 7.98%
- Cap rate (6%) < loan constant (7.98%) = negative leverage
- Cash flow: $60K - $55,884 = $4,116
- Cash-on-cash: $4,116 / $300K = 1.4%
Same property. Same cap rate. Same equity. But the loan constant exceeds the cap rate by nearly 200 basis points. Your equity return collapsed from 8.3% to 1.4%. A savings account pays more.
Notice the trap: the stated interest rate is 7%, and the cap rate is 6%. That 1% gap looks manageable. But the loan constant is 7.98%, meaning the actual gap is 1.98%. Comparing cap rate to interest rate would have understated the damage by half.
Why This Matters More in 2026
Between 2010 and 2022, interest rates were so low that almost every CRE deal was positively levered. A 5% cap rate property looked great because you could borrow at 3%. The 200 basis point spread juiced equity returns.
That era is over. The Fed raised rates dramatically in 2022 and 2023. By 2024, commercial loan rates were sitting at 6-7% for stabilized multifamily and higher for riskier asset types. Meanwhile, cap rates lagged. They didn't expand at the same pace because sellers refused to accept lower prices and capital was still chasing deals.
The result: a lot of deals in 2023 and 2024 were closed at negative leverage. Buyers paid 5% cap rates while borrowing at 7%. They didn't notice because their pro formas projected rent growth that would expand NOI and "fix" the leverage problem in year 2 or 3.
Sometimes that worked. Often it didn't. NBER research found that 14% of all CRE loans were in negative equity by 2023. The buyers who underwrote based on cap rate compression and rent growth got squeezed when neither materialized.
The Three Times Negative Leverage Is Defensible
Negative leverage is not always disqualifying. There are three scenarios where it can make sense:
1. Value-add with credible execution. You buy at a 5% cap rate against a 7% interest rate. The in-place rents are 20% below market. Your business plan involves renovating units and pushing rents over 18 months. By year 2, the stabilized cap rate (your renovated NOI divided by purchase price) is 7.5%. Now you have positive leverage. The negative leverage was a cost of acquiring a property you could improve.
This requires three things: a clear renovation plan, market rents that actually support your projections (verified by rent comps, not broker pro forma), and enough capital reserves to cover the negative cash flow during the value-add period.
2. Trophy assets in primary markets. Institutional buyers occasionally accept negative leverage on Class A properties in primary markets because the appreciation thesis dominates the cash flow thesis. They're paying for liquidity, prestige, and long-term value preservation. This is not the play for individual investors.
3. Tax sheltering with passive losses. High-income investors sometimes buy negatively-levered properties specifically because the depreciation generates tax losses that offset other income. The deal "loses money" on a cash basis but improves the investor's overall tax position. This requires careful tax planning and is not a standalone investment thesis.
When Negative Leverage Is a Trap
If none of the three scenarios above apply, negative leverage is a trap. Here's what it usually looks like:
- You bought a stabilized property at a compressed cap rate because the market was hot.
- You assumed you could refinance into a lower rate later "when rates drop."
- Your business plan doesn't include a credible NOI improvement story.
- Your cash flow is negative or marginal in year 1.
- You're counting on appreciation to bail you out at sale.
This is not investing. It's speculating. You are paying the lender to hold an asset that doesn't generate enough income to cover its own debt service. Every month, you are reducing your equity to pay for the privilege of owning a building.
The clearest tell: if someone describes the deal as "the numbers don't quite work today, but rents are growing in this submarket," they are describing negative leverage that depends on future events. That's not analysis. That's hope.
How to Check Leverage in 30 Seconds
Before you fall in love with any deal, run this calculation:
- Calculate the cap rate (NOI / Purchase Price).
- Calculate the loan constant (annual debt service / loan amount). For a quick estimate: multiply your monthly payment by 12, then divide by the loan amount.
- Subtract loan constant from cap rate.
If positive: positive leverage. Borrowing helps you. If negative: negative leverage. Borrowing hurts you.
Do not substitute the interest rate for the loan constant. That comparison is only accurate for interest-only loans.
The Quick Screen tool on this site calculates the loan constant from your loan terms and compares it to the cap rate automatically. It flags negative leverage in red. The red flag isn't always disqualifying, but it forces you to articulate why you're accepting it. If you can't, you shouldn't be doing the deal.
The Bias Check for Leverage
- What's my cap rate?
- What's my loan constant (not interest rate)?
- Is the spread positive or negative?
- If negative, do I have a credible business plan to get to positive leverage by year 2?
- If yes, what specific assumptions does that depend on, and how sensitive is the plan to those assumptions being wrong?
- If I had to refinance at today's rate, would the deal still pencil?
- What's my leverage ratio? At 75% LTV that's 4x. Am I prepared for 4x amplification of downside?
The Mental Model: The Leverage Decision Tree
Before you accept any loan terms, run through this sequence:
Step 1: Is leverage positive or negative? Cap rate minus loan constant. Positive = leverage helps. Negative = leverage hurts. If you do not know your loan constant, you do not know the answer to this question.
Step 2: If negative, do you have a credible path to positive? Value-add with documented rent comps? Renovation plan with contractor bids? Lease-up with signed LOIs? If the path is "rates will drop" or "rents will grow," that is hope, not a plan.
Step 3: Can you survive the negative period? Calculate total negative cash flow from closing until projected positive leverage. Do you have reserves to cover it? What happens if the timeline extends 6 months?
Step 4: What is your leverage ratio, and are you prepared for that amplification? At 75% LTV, a 10% property value decline means a 40% equity loss. At 80% LTV, it is a 50% equity loss. Know the number. Accept it or reduce it.
If you pass all four steps, you have an informed leverage decision. If you skipped any step, you have a guess.
Where to Go Next
- How does leverage affect your financing? Read DSCR Explained for the lender's perspective on your debt.
- What does the cap rate actually tell you? Read What Is a Good Cap Rate to understand the growth bet embedded in your going-in yield.
- How to underwrite a value-add deal with negative leverage. Read How to Underwrite a Multifamily Deal for the full institutional framework.
Sources
- Geltner et al., "Commercial Real Estate Analysis and Investments," 2nd Edition (2007), Chapter 13: Use of Debt, pp. 297-318
- NBER Working Paper 31970, "Monetary Tightening, Commercial Real Estate Distress, and US Bank Fragility" (2023)
- CFA Institute, "The Interplay Between Cap Rates and Interest Rates" (2024)
- Federal Reserve Bank of St. Louis, "Stress Testing Banks on Commercial Real Estate" (2023)