Office space is typically priced at $40–$120 per square foot per year depending on city, neighborhood, and lease structure. To estimate your monthly rent, multiply your square footage by the annual rate and divide by 12. Lease structure matters as much as the headline number — a gross lease and a triple-net lease at the same price per square foot can cost you thousands of dollars more per month.
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What Does "Price Per Square Foot" Actually Mean for Office Space?
If you've ever bought a home, you've seen price-per-square-foot used to compare properties quickly. Commercial leasing works the same way, with one key difference: the number is almost always an annual rate, not a purchase price.
So when a broker says a space is "$65 per square foot," they mean $65 per square foot per year, paid in monthly installments.
Here's the basic formula:
Monthly rent = (Square footage × $/sqft/year) ÷ 12
Example:
- 1,500 sqft at $65/sqft/year
- Annual rent: $97,500
- Monthly rent: $8,125/month
Simple enough. But here's where things get confusing: the square footage number itself isn't always what it seems.
Rentable vs. Usable Square Feet
This is one of the most important things to understand before you sign anything.
- Usable square feet (USF): The actual square footage of your suite — the space your team physically occupies.
- Rentable square feet (RSF): Usable square feet plus a proportional share of common areas — lobbies, hallways, shared bathrooms, mechanical rooms. This is what you're billed on.
The difference between RSF and USF is called the load factor, or "loss factor." It typically runs 10–25% in commercial buildings. A space quoted at 2,000 RSF might only have 1,600–1,700 square feet of actual office.
Two spaces with identical rentable square footage and identical price per square foot can feel very different in practice. Always ask for the usable square footage.
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How to Calculate Your Real Monthly Office Cost
The headline $/sqft number is just the starting point. What you actually pay depends on the lease structure.
Full-Service Gross Lease
A full-service gross (FS) lease is the most common structure in Class A multi-tenant office buildings, especially in San Francisco and New York. The landlord bundles most operating costs — utilities, janitorial, property taxes, insurance, building maintenance — into one per-square-foot price. What you see is mostly what you pay.
FS Example:
- 1,200 RSF at $72/sqft/year FSG
- Monthly base rent: $7,200/month
- Likely add-ons: internet ($200–$500 / month), furniture, HVAC overtime if your team works late
Modified Gross Lease
A modified gross (MG) lease quotes a lower base rent, but you pay separately for some operating expenses. This structure is more common in smaller buildings and standalone properties. The base rate looks cheaper. Sometimes it is, sometimes it isn't.
MG Example:
- 1,200 RSF at $52/sqft/year
- Annual expenses: ~$3–$5/sqft/year (CAM, utilities, janitorial, water)
- Effective cost: $55–$57/sqft/year all-in
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The Hidden Costs Beyond Price Per Square Foot
The $/sqft number is never the full story. Founders signing their first lease consistently underestimate what hits in the first 30–90 days. Here's what actually catches people off guard:
- HVAC overtime: Most buildings only provide heating and cooling during standard business hours (typically 8am–6pm, Mon–Fri). Work late or on weekends and you'll pay an hourly fee — often $50–$150/hour. If your team regularly grinds past 7pm, this adds up fast.
- Furniture: A raw or lightly furnished space costs $1,000–$5,000 per person to set up properly — desks, chairs, conference tables, storage. See our guide on furnished office space for startups for how to weigh furnished vs. unfurnished options.
- Cleaning: Many FS leases include janitorial service, but frequency and scope vary. Verify before you sign.
- Insurance: Landlords require commercial general liability and property insurance. Budget $500–$1,000/year for a small office.
- Tenant improvement (TI) buildout: Negotiate a TI allowance from the landlord upfront — it's real money on the table. If you have leverage, the landlord can cover your buildout. If not, you mightbe be on the hook.
A practical rule of thumb: add 10–20% to your base rent estimate to get closer to your true all-in monthly cost.
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How Much Space Does Your Team Actually Need?
Getting square footage right matters as much as price per square foot. Lease too little and you're cramped within a year. Lease too much and you're paying for empty desks.
The standard benchmark is 120–150 square feet per person for rentable square footage, but it shifts based on how your team works:
|
Team Type |
Sqft/Person (RSF) |
|---|---|
|
Engineering-heavy (mostly heads-down) |
100–120 sqft |
|
Mixed roles, moderate meeting needs |
120–140 sqft |
|
Sales, client-facing, or conference-heavy |
140–175 sqft |
|
Executive / investor-facing office |
175–200+ sqft |
Plan for growth. If you're signing a 24-month lease today with 8 people but expect to hit 14 by month 18, size for 12–14 from the start. Breaking a lease early costs far more than a few months of paying for extra desks.
One thing founders overlook: conference room density. A team of 10 with two salespeople who run back-to-back demos will burn through meeting room time constantly. If that's your situation, weight toward the higher end of the range — or look for buildings with shared conference facilities you can book on demand.
For more on sizing as you scale, read how to estimate office square footage for a scaling team.
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How to Actually Compare Spaces on Price Per Square Foot
When you're looking at two or three spaces side by side, raw $/sqft comparisons only work if you're comparing like-for-like. Run through this before you draw any conclusions:
- Confirm both are quoted in RSF — if one space quotes usable and one quotes rentable, adjust before comparing
- Confirm lease structure — FSG vs. modified gross vs. NNN changes the effective cost by $10–$25/sqft
- Check what's included — internet, cleaning, HVAC hours
- Factor in TI allowance — a space offering $20/sqft toward buildout is effectively cheaper than it looks
- Calculate deposit requirements — 3 months vs. 6 months is real working capital tied up
- Model total cost of occupancy — base rent plus hidden costs, times lease term length
If you want help running the comparison, Tandem's leasing team works with founders directly — sourcing spaces, running the math, and negotiating terms — at no cost to the tenant.
Last updated: October 2026
