People ask me this all the time. “How did you come up with that number?” Fair question. Here’s the honest answer: it’s math. Not gut feel, not some formula I saw on YouTube, not whatever some broker thinks the market will bear. It’s actual math based on what the property is doing today.


  • Audit Your Actual Gross Rent: Sum every lease’s actual rent, not potential. Don’t count vacant units or spaces with tenants in negotiation. Use 12 months of collected rent.

  • Calculate Real Operating Expenses: Get last 2 years of P&L or utility bills, insurance statements, tax bills, maintenance invoices. Use the higher of the two years to be conservative.

  • Understand Your Market’s Cap Rate: What are comparable buildings trading at in your market? Industrial Charlotte: 6.5-7%. Retail Charleston: 7-8%. Your property’s cap rate depends on type and location.

  • Know Your Problem List: Deferred maintenance, vacancy, short leases, tenant quality. Quantify each. This tells you where you’re vulnerable in negotiation.

  • Test Buyer Math Yourself: Calculate your NOI, apply a reasonable cap rate, and see what price emerges. If a buyer’s offer differs, understand why — cap rate disagreement or NOI calculation difference?

Step one: What’s it earning?

If the building is leased, I start with the income. Actual rents being collected. Not what the tenant “should” be paying or what the broker’s pro forma says. I want to see the rent roll and the bank statements. Or at least the last 12 months of income and expense.

Reverse-engineer your buyer’s offer

If a buyer offers you $1.8M for your property, here’s how they got there.

  1. What actual rent are they crediting (collected, not potential)?
  2. What operating expenses are they deducting?
  3. What NOI did they calculate?
  4. What cap rate did they apply?
  5. What problem costs did they deduct?

I calculate net operating income by taking gross rent and subtracting real expenses. Property taxes, insurance, maintenance, management (even if you’re self-managing, I factor in what a manager would cost), and reserves for capital items. That gives me NOI.

Step two: Apply a cap rate

NOI divided by cap rate equals value. The cap rate depends on the asset type, location, tenant quality, building condition, and lease terms. A fully leased flex building in Charlotte with strong tenants on 3-5 year NNN leases? Maybe a 7 cap. A partially vacant industrial building in a secondary market with deferred maintenance? More like an 8.5 or 9 cap.

I don’t pick cap rates out of thin air. I look at what similar buildings have actually sold for recently. Comparable sales tell me where the market is. I adjust up or down based on the specific property’s characteristics.

Step three: Subtract the problems

This is where a lot of sellers get frustrated. But it’s the most important step. If the roof needs replacing, I’m deducting $8-12/SF. If the parking lot is cracked, that’s another $4-6/SF. If there’s vacant space, I’m deducting the cost to get it leased: TI, commissions, and carrying costs during the vacancy.

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    These aren’t negotiation tactics. They’re actual costs I’m going to spend after I close. Between 20 commercial deals and over a hundred residential properties, I know exactly what a roof costs, what paving costs, what tenant improvements cost in this market. There’s no guesswork.

    Step four: Sanity check

    I compare my number against replacement cost. What would it cost to build this building new today? In the Carolinas, new construction runs $130-150/SF for industrial and flex. Older buildings in decent shape typically trade at 60-80% of that. If my math puts the value below that range, the deal probably doesn’t make sense for me. If it’s above that range, the seller’s expectations might be too high.

    I also look at price per square foot relative to recent sales. If similar buildings in the area have been selling at $100-120/SF and my number comes in at $85, I need to understand why. Usually it’s the capital items or a lease situation that justifies the discount.

    The result

    My offer is a number I’ve worked through carefully. It’s fair. It’s based on real data. And it’s a number I won’t try to change after you accept it. No re-trading. What I offer is what I close at.

    Seller takeaway

    If you’re selling commercial property and want to understand how buyers calculate offers, call Roth Capital at 704-600-3839. Jim Kittridge will walk through the math and show you exactly what price he’d pay and why.

    Want to know what I’d pay for your property? Whether it’s a storage facility or a flex park or anything in between, I’ll run the numbers and give you a straight answer. 704-600-3839.

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    Tell us about your property. We will follow up within one business day.

      Jim Kittridge

      Founder of Roth Capital. Direct buyer of commercial and industrial properties across North Carolina and South Carolina.