Office space calculator

How the office space calculator works

The quick way to size an office is headcount times square feet per person. That answers the question for a team that is in every day. For a hybrid team the useful question is how many people are in on the busiest day, because that is the day the office has to hold. The calculator works it out in six steps:

A worked example

The calculator starts with 20 people who come in 3 days a week and pick their own days. An average day has 12 people in, and the busiest day about 15. With 10% spare that is 17 desks. In a mixed layout each desk needs 79 sq ft for itself, 40 sq ft of meeting rooms and common space, and 40% on top for walkways: about 2,830 usable square feet, or 3,260 rentable once the building’s share is added. At a placeholder rent of $40 per square foot per year, that is $130,281 a year. The same team working full time in the office needs 20 desks and 3,830 rentable square feet, so the hybrid pattern saves $22,991 a year in rent.

How much office space do I need per employee?

There is no single right number, and the published ones measure slightly different things: per person or per desk, usable area or net internal area, with or without meeting rooms. Read them as a range. They mostly fall between about 110 and 180 square feet (10 to 17 m²) per person, all in.

The layout presets come from the same sources. Open plan and private offices use the Defense Department planning figures, and mixed uses Washington State’s baseline. The trend runs one way: US federal agencies have cut their benchmark from 180 to 150 usable square feet per person, and the Department of Transportation is replacing 8 by 10 foot workstations with 6 by 8 foot ones (GAO, July 2026).

How much does office space cost per employee?

Multiply the space per person by the rent. In the US, two national trackers put office rents at $32.80 per square foot a year (Yardi Matrix, national full-service equivalent listing rate, March 2026) and $37.95 (CBRE, average asking rent, the third quarter of 2026). At the federal benchmarks of 150 to 180 usable square feet per person, plus 15% for the building’s common areas, rent alone comes to about $5,700 to $7,900 per employee per year, or $470 to $650 a month, for a team in the office every day.

Location moves it more than anything else. Manhattan listings averaged $69.80 in the same Yardi data, which puts the same space at $12,000 to $14,400 per person. The two trackers also measure different things: Yardi’s is a full-service equivalent rate, which folds in the building’s operating costs, and both are asking or listing rents, not what tenants end up signing for. Use a quote for your own building when you have one. A hybrid team that shares desks rents fewer desks, so its cost per employee falls; the comparison under the calculator shows by how much.

Size for the busiest day, not the average

A three-day policy does not mean 60% of the team on every weekday. People cluster in the middle of the week. Kastle, which counts each person's first entry of the day in buildings using its access control in ten US cities, reported a 56.1% weekly average for the week ending 21 October 2026, with Tuesday the busiest day at 66.1% (Kastle Back to Work Barometer). That is 1.18 times the average, which is where the calculator’s default of 1.2 comes from. Kastle measures against a February 2020 baseline, not against desks, so treat the ratio as a starting point and use your own badge or booking data once you have it.

If you set anchor days, where the whole team comes in on the same days, those days are full, and the office has to fit everyone no matter how few days a week it is. Pick “Everyone on the same days” in the calculator to see it. If you know your weekly shape, “Set each weekday” takes the highest day. For the trade-offs between fixed and flexible days, see how to set a hybrid work schedule.

Desk sharing in plain words

A desk-sharing ratio is desks divided by people on the team. 1.0 is a desk each. 0.6 is 6 desks for every 10 people, which works only if no more than about 6 in 10 turn up on the busiest day.

• Public employers plan on sharing. Washington State gives people who are in the office less than 60% of the time a third of a full-time allocation, a goal of three people per workspace (State Facility Space Use Guidelines).
• Frequent visitors keep their desks. The US Department of Transportation gives a dedicated desk to people who are in six days or more per two-week pay period (GAO).
• Sharing needs a way to find a desk. Below a desk each, people need to know where they will sit. A booking tool or team zones do that; a policy on paper does not.

Why fewer office days don’t shrink the office in step

Going from five office days to two does not cut the space by 60%. Here is a team of 40 with the calculator’s default settings:

• The busiest day sets the size. At four days, the busiest day is close to full, so there is nothing to save.
• Anchor days cancel sharing. If everyone comes in on Tuesday, Tuesday needs a desk for everyone.
• People come in to meet. The office days are the collaboration days, so meeting rooms, phone booths and team tables are busier per person in a hybrid office. Raise the common area per desk if that is how your team uses it.
• Leases come in steps. Floors and suites have fixed sizes, and leases run for years. Size for the team you expect to have, not the one you have today.

Downsizing office space for a hybrid team

If the office feels empty most days, it is probably sized for a full-time team. Before you change the lease, get the numbers straight:

1. Measure the busiest day. Count people in on each weekday for a few ordinary weeks, from badge data, desk bookings or a simple headcount. The busiest day sets the size, not the average.
2. Decide how desks are shared. Shared desks sized to that day, plus a few spare, are where the savings come from. If the team works best on shared anchor days, sharing saves little, and that is a valid choice.
3. Turn spare desks into the rooms people come in for. Meeting rooms and quiet spaces are often what a hybrid office is short of.
4. Look at the lease options. The usual routes are subletting part of the space, if the lease allows it, or taking a smaller space when the lease comes up for renewal. Notice periods, break clauses and sublet terms differ in every lease, so read yours and get advice before you act; this page is not legal advice.

Usable and rentable area

The space you occupy is the usable area. Rent is usually charged on the rentable area, which adds your share of the building’s lobby, lifts, toilets and plant rooms. The percentage between the two is the load factor. Washington State adds 15% for building services in its baseline (OFM), and it varies by building, so ask the landlord for both figures and the measurement standard behind them. If a price is quoted on the space you occupy, set the load factor to 0.

Inside your own space, walkways take room too. The Defense Department’s planning criteria add 12% for all private offices up to 28% for all open plan (Admin BFR Generator), and Washington State adds 40%. The presets fill in a figure for each layout.

What the rent figure leaves out

The comparison counts rent, plus home-office budgets if you enter them. An office also costs service charges, fit-out and furniture, utilities, cleaning, insurance and IT, all on top of the rent. Remote work is not free either: home-office budgets, coworking passes and travel to meet in person move the cost rather than remove it. And the trip to the office costs your team time and money. The commute cost calculator puts a yearly figure on it, and the Office Days Index shows how many office days employers actually require, with a source for each company. For the wider decision, including what remote teams spend instead, read hybrid vs remote work.

Written and maintained by the DoneThat team. The formulas match the calculator code, and the benchmarks above were last checked against their sources on 3 November 2026. This is a planning estimate, not a quote or professional advice.

Frequently asked questions