What Is Occupancy Capacity and How Is It Calculated?
Capacity is the maximum number of people who can be safely in a space at the same time. Knowing the capacity of a venue, hall, or event is not a decision made by the organizer, but is regulated by fire safety regulations.
What is capacity at an event, concert, venue, or conference?
Capacity is the maximum number of people a space can hold, calculated to ensure that everyone can evacuate safely in case of an emergency. This applies to both permanent establishments (bars, shops, offices) and temporary events (concerts, festivals, fairs).
How is capacity calculated?
Capacity is calculated by dividing the usable area of the space by the occupancy density established by regulations according to the use of the premises. The basic formula for calculating occupancy capacity is:
Occupancy Capacity = Usable Area (m²) ÷ Occupancy Density (m²/person)
In Spain, the reference regulations are the Technical Building Code of The Building Code, Basic Document on Fire Safety (CTE DB-SI), in its Table 2.1 of Section SI 3. This is the law of capacity control at events that applies throughout the national territory, and assigns a different occupancy density according to the use of the space:
| Space Type | |
|---|---|
| Public seated areas | 0.5 – 1.5 m²/person |
| Discos | 0.5 m²/person |
| Shops (sales areas) | 2 – 5 m²/person |
| Offices (public areas) | 2 m²/person |
| Classrooms | 1.5 m²/person |
Practical example: how to calculate the capacity of a space
A 100 m² space for standing audiences (such as a concert area) with a density of 0.25 m²/person:
Capacity = 100 m² ÷ 0.25 m²/person = 400 people
