Occupancy load calculator

Calculate occupant loads and egress requirements per IBC

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The Occupancy Load Calculator helps architects and designers determine the maximum number of occupants for any space based on International Building Code (IBC) requirements.

Occupant load directly impacts egress design, plumbing fixture counts, and fire protection requirements. Getting this calculation right early in design prevents costly revisions during code review.

Select your occupancy type, enter the floor area, and instantly see the calculated occupant load along with implications for exit width, number of exits, and travel distance requirements.

Features

Everything you need

IBC occupant load factor database
Multiple occupancy type support
Automatic egress width calculations
Exit quantity requirements
Travel distance guidelines
Mixed-use building support
Metric and imperial units

How it works

Simple workflow

1
Select the occupancy classification (Assembly, Business, etc.)
2
Choose the specific function within that classification
3
Enter the floor area of the space
4
Review the calculated occupant load
5
Check the resulting egress requirements

Use cases

Built for real-world scenarios

Restaurant design

Determine maximum seating capacity based on dining area square footage and applicable load factors.

Office space planning

Calculate occupant loads for tenant improvements and verify existing egress capacity.

Assembly spaces

Determine code-compliant capacity for auditoriums, gyms, and event venues.

Permit applications

Generate accurate occupant load calculations for building permit submissions.

FAQ

Frequently asked questions

Occupant load factor is the floor area per person used to calculate maximum occupancy. For example, an office has a factor of 150 sq ft per person (gross), meaning a 15,000 sq ft office has an occupant load of 100 people.

IBC defines occupancy groups based on building use: Assembly (A), Business (B), Educational (E), Factory (F), High Hazard (H), Institutional (I), Mercantile (M), Residential (R), Storage (S), and Utility (U).

Concentrated occupancy (like theater seating) uses smaller load factors, resulting in higher occupant counts. Unconcentrated (like dining with tables) uses larger factors. The IBC specifies which applies to each use.

Generally: 1-49 occupants = 1 exit, 50-500 = 2 exits, 501-1000 = 3 exits, over 1000 = 4 exits. High-hazard and certain assembly uses have stricter requirements.

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