What this calculator does
Building codes set a maximum occupancy for most spaces based on how much floor area is allocated per person, a figure called the occupant load factor. This calculator divides a given floor area by a chosen load factor to estimate maximum occupancy, with a few common reference factors offered as a starting point for different space types.
Occupant load factors vary considerably by the type of space and by the specific building code in force in a given jurisdiction: a densely-packed standing area (like a concert floor) needs far less space per person than an office. The factors offered here are common, general reference points, not a substitute for checking the actual local building code or fire authority requirement for a specific space.
The formula
Divide the floor area by the occupant load factor (expressed as square metres per person) to get the maximum number of occupants, rounding down to a whole number of people.
| Term | Meaning |
|---|---|
| Occupant load factor | The floor area allocated per person for occupancy calculations, in square metres per person, which varies by the type of space. |
| Maximum occupancy | The greatest number of people a space is calculated to safely hold, based on its floor area and the applicable load factor. |
The inputs explained
| Field | What to enter |
|---|---|
| Floor area (m²) | The floor area of the space being assessed. |
| Space type (sets a common reference factor, editable) | A common reference load factor for different space types, or choose Custom to enter your own. |
| Occupant load factor (m² per person) (m²) | The occupant load factor in square metres per person, used only if Custom is selected above. |
When to use it
Planning an event space
Before booking or setting up a venue, a rough occupancy estimate from floor area and the venue's intended use helps check the space against expected attendance.
Reviewing a fit-out or renovation
Changing a space from one use to another (say, from open-plan office to dense meeting rooms) can change its effective occupant load factor and therefore its maximum legal occupancy.
A quick sanity check against a stated capacity
Comparing a venue's advertised maximum capacity against a rough area-based estimate can highlight whether the stated figure seems reasonable for the type of space.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How does maximum occupancy change by space type, for a fixed 200m² area?
The same 200m² floor area assessed against different common space-type load factors.
| Space type | Maximum occupants |
|---|---|
| Dense assembly | 200 people |
| Seated assembly | 133 people |
| Retail | 66 people |
| Office | 20 people |
| Warehouse | 6 people |
Questions
Are these load factors legally binding?
No. The factors offered here are common, general reference points used across various building codes, not a specific jurisdiction's legal requirement. Always confirm the exact factor and any other occupancy rules with the local building code or fire authority for the specific space and its actual use.
Why does the load factor vary so much between space types?
Different activities need different amounts of space per person for safe movement and, especially, safe evacuation. A densely-packed standing crowd needs far less space per person than people seated at desks or shopping in aisles.
Does this account for exits and evacuation routes?
No, this only estimates occupancy from floor area and a load factor. A full occupancy assessment under most building codes also considers exit width and travel distance, which can further limit the legal maximum below a pure area-based estimate.
Can I use my own load factor?
Yes, select Custom and enter the exact occupant load factor specified for your space by the relevant building code or a qualified professional.
For a related area calculation before applying an occupancy factor, see the square metre calculator.