Why CRE Loan Calculators Get Your Proceeds Wrong (And How to Find One That Doesn’t)

If you’ve ever used an online calculator to estimate your CRE loan proceeds and thought “that can’t be right” — you were probably correct.

The problem is debt yield, and most calculators either ignore it entirely or apply it wrong.

What debt yield actually is

Debt yield is net operating income divided by loan amount, expressed as a percentage: NOI ÷ Loan Amount. CMBS lenders require it to hit a floor — typically 10% or higher — before they’ll fund at the requested proceeds. Conventional banks set the bar at 8–9%.

That’s not a rounding error. On a $12 million loan request with a $1,000,000 NOI, the difference between a lender with an 8.5% floor and one with a 10% floor is the difference between a $11.76M max loan and a $10M max loan — a $1.76 million gap that no rate negotiation, longer amortization, or stronger appraisal can close.

Why most calculators fail

Generic CRE calculators are built around two metrics: LTV and DSCR. They assume you can calculate loan size from property value and payment coverage alone.

The problem is lenders don’t fund whichever number those two metrics suggest. They fund the lowest result of LTV, DSCR, and debt yield. A calculator that skips debt yield always returns the most optimistic number — which is almost never the number on your term sheet.

The second failure is using pro forma NOI instead of underwritten NOI. Most tools take whatever you input at face value. Real lenders apply a market vacancy factor (5–10%), a replacement reserve ($0.15–$0.25 per square foot), and haircut miscellaneous income. A $1,100,000 pro forma NOI routinely becomes $1,012,000 after underwriting — and that $88,000 gap represents $880,000 of lost loan capacity at a 10% CMBS floor.

What an accurate calculator needs

To produce a realistic CRE loan estimate, a calculator has to:

• Apply the actual debt yield formula and compare it against the lender’s specific minimum floor
• Run LTV, DSCR, and debt yield simultaneously and surface whichever constraint is binding
• Show the maximum loan each metric supports so you know exactly where your ceiling is
• Let you model different lender floors — 8.5% for a bank, 10% for CMBS — against the same deal

Most free tools only handle DSCR and LTV accurately. The debt yield piece — the one that surprises borrowers on closing day — is where they fall apart.

A calculator that gets it right

I’ve been using Debt Yield Calculation for CRE estimates. You enter NOI, loan amount, interest rate, amortization, and property value, and it runs all three constraints — showing you which one is binding and what your actual maximum loan is under each metric, side by side.

There’s also a dedicated CRE Loan Sizing Calculator if you want to compare what the same NOI supports across different lender types — useful when you’re evaluating a CMBS execution versus a portfolio bank before you spend time on a full package.

Both tools are free, run in your browser, and don’t require a sign-up. The debt yield calculator also compares your result against typical lender minimums by lender type, so you can see at a glance whether your deal clears before you pick up the phone.

The bottom line

If your term sheet came back lower than your calculator predicted, it was almost certainly debt yield. A $1,000,000 NOI property at a 10% CMBS floor supports a maximum loan of $10,000,000 — regardless of what LTV or DSCR show. That number won’t move by negotiating the rate. It moves when NOI goes up or the loan goes down.

Run debt yield first, before you submit anything.