Maximum Occupancy Calculator
Maximum Allowed Occupancy
Total Area: 0 sq ft
Load Factor Used: 0 sq ft per person
Understanding Maximum Occupancy Calculations
Maximum occupancy is the total number of people permitted to occupy a building or specific room at any given time. This limit is strictly enforced by local fire marshals and building inspectors to ensure life safety, efficient egress during emergencies, and proper ventilation.
The Core Formula
The standard calculation used by the International Building Code (IBC) and NFPA 101 (Life Safety Code) is relatively straightforward:
Factors Affecting Occupancy
- Floor Area: Calculated by multiplying the clear length and width of the room. This usually refers to "net" area, which excludes permanent fixtures like thick walls or large columns.
- Usage Type: Different activities require different amounts of space. For example, a standing-room concert hall (7 sq ft per person) can legally hold much more than an office space (150 sq ft per person).
- Exit Capacity: Even if a room is huge, the number of people allowed may be limited by the number and width of available exits.
Standard Occupancy Load Factors
While local codes may vary, here are the most common factors used in North America:
| Room Use | Sq Ft per Person |
|---|---|
| Assembly (Chairs Only) | 7 sq ft |
| Dining (Tables & Chairs) | 15 sq ft |
| Classrooms | 20 sq ft |
| Commercial Kitchens | 200 sq ft |
Example Calculation
Suppose you have a conference room that is 30 feet long and 20 feet wide, and you plan to set it up with tables and chairs for a workshop.
- Calculate Area: 30 ft × 20 ft = 600 sq ft.
- Identify Factor: Tables and chairs assembly uses a factor of 15.
- Divide: 600 / 15 = 40.
- Result: Your maximum legal occupancy is 40 people.
Disclaimer: This calculator is for estimation purposes only. Always consult with your local fire department, building inspector, or a licensed architect to ensure compliance with local ordinances and the specific configuration of your building.