How Much Office Space Do You Need? From Headcount to a Floor Size in Four Steps

Step one: pick the headcount, then the density

The headcount to use is the one you expect 12 to 18 months from now, because a lease lasts years. Then choose how the team sits:

• 50 people in a dense open plan, about 140 square feet each: 7,000.
• 50 people at the standard 175: 8,750.
• 50 people with mostly private offices, about 225 each: 11,250.

Most companies start at 175 and move off it only when they know they are unusual.

Step two: adjust for hybrid and for hiring, once each

A hybrid schedule removes desks and adds demand for rooms, so the saving is smaller than attendance figures suggest: 10 to 20 percent. For 50 people at the standard figure that brings the floor to between 7,000 and 7,875 square feet.

Hiring works in the other direction. If step one used today's headcount, add 15 to 25 percent: for a company of 50 with open roles, roughly 10,060 to 10,940 square feet. If it already used the headcount you expect in 12 to 18 months, skip this, because the growth is inside that number.

Apply each adjustment one time. Entering a reduced headcount and then also taking a hybrid discount cuts the space twice, and adding a growth margin to a future headcount pads it twice.

Step three: check the rooms already inside the number

The per-person figure is all-in. For 50 people a standard layout spends its 8,750 square feet roughly like this:

• Open desks, at around 60 square feet a seat: 3,000.
• Circulation, meaning aisles and corridors: about a third of the floor, a little over 2,900.
• Everything else, some 2,830: around six meeting rooms, eight or nine call booths, a pantry, reception and storage.

If your plan calls for more rooms than that, the total goes up. The 50-person guide walks through the layout in detail.

Step four: turn rentable into usable before comparing floors

New York landlords quote rentable square feet, a measure that takes in a share of the lobbies, corridors and mechanical rooms. The area you can furnish is 15 to 25 percent smaller. An 8,750 square foot lease leaves roughly 6,560 to 7,440 square feet of usable floor.

The 175 figure already allows for the difference, so do not add it again. It matters when two floors lose different amounts: compare those on usable feet. Rentable and usable square feet shows how.

The sizing mistakes that lead to a second move

• Sizing to today's headcount and outgrowing the floor inside the term.
• Sizing to the most optimistic hiring plan and paying for desks nobody fills.
• Counting desks and forgetting rooms. Tenants finishing a first buildout most often wish they had added more call booths.
• Comparing floors by rentable area when their loss factors differ.
• Trusting the arithmetic over the floor itself. Where the core, columns and windows sit can move the seat count by several desks, which a test fit will show.