How to Calculate Commercial Lease Price Per Square Foot (With Calculator)

Staring at a commercial lease document that quotes an annual rate for an office space doesn't actually tell you if you can afford it. We have all been there, sweating over the raw numbers and wondering why commercial real estate feels intentionally confusing. The problem is that leasing agents use jargon designed to obscure the true cost.

The solution is to strip away the fluff and master how to calculate price per square foot for a commercial lease. The math to figure this out is straightforward.

The Basic Commercial Lease Formula

Most commercial properties quote their rent as an annual price per square foot. If you are looking at an office space and the broker says it is "$30 a foot," they mean it costs $30 per square foot per year.

To find your actual base rent, you simply multiply that rate by the total square footage of the space.

Annual Lease Rate × Total Rentable Square Footage = Total Annual Rent

For example, if you are eyeing a 2,500 square foot office space listed at $28 per square foot:

1. Multiply 2,500 by $28.
2. Your total annual base rent is $70,000.
3. Divide by 12 to find your monthly base rent: $5,833.33.

If you already know the monthly rent and the size of the space, use this formula to work backward:

(Monthly Rent × 12) ÷ Square Footage = Annual Price Per Square Foot

The Trap: Rentable vs. Usable Square Footage

Here is where the math gets brutal. In commercial leasing, the square footage you use is rarely the square footage you pay for.

If you measure the inside walls of your specific office, that is your Usable Square Footage (USF). But landlords will charge you based on the Rentable Square Footage (RSF), which includes a prorated share of the building's common areas (lobbies, shared bathrooms, hallways, and elevators).

Base Rent vs NNN (Triple Net)

When learning how to calculate price per square foot for an office space, you must differentiate between Gross leases and Triple Net (NNN) leases.

If a space is listed at $25/sq ft NNN, and the estimated Common Area Maintenance (CAM), taxes, and insurance is $10/sq ft, your true cost is actually $35/sq ft. Always factor in the NNN costs when running your price per square foot calculation.

Check out our guide on commercial vs residential price per square foot to understand why these markets use completely different valuation metrics.

Crunch the Numbers

Stop guessing and let the math do the work for you. Use our calculator below to get an instant answer.