Building Occupancy Load Calculator
Calculate the maximum occupancy load for a building space based on floor area and occupancy type per the International Building Code (IBC) Table 1004.5.
Formula
Occupancy Load (per floor) = ⌈ Floor Area (sq ft) ÷ Load Factor (sq ft/person) ⌉
Total Occupancy Load = Occupancy Load per Floor × Number of Floors
Per IBC Section 1004.1, fractional occupant loads are rounded up to the next whole number (ceiling function).
Minimum Egress Width (IBC 1005.1):
- Stairways: Total Occupancy × 0.2 inches
- Other egress components: Total Occupancy × 0.15 inches
Unit Conversion: 1 m² = 10.7639 sq ft
Assumptions & References
- Load factors are taken from IBC Table 1004.5 (International Building Code, 2021 edition).
- Occupant load is calculated using gross floor area unless the occupancy type specifies net floor area (e.g., educational classrooms use net area).
- Fractional occupant loads are always rounded up per IBC Section 1004.1.
- Egress width factors are per IBC Section 1005.1: 0.2 in/person for stairways, 0.15 in/person for all other egress components.
- Special-purpose industrial occupancies have no standard load factor; occupant load must be determined by a licensed engineer (IBC 1004.5).
- This calculator does not account for mixed-use occupancies, mezzanines, or areas with fixed seating — consult IBC Section 1004.6 for those cases.
- Local amendments to the IBC may apply. Always verify results with the local Authority Having Jurisdiction (AHJ).
- Results are for preliminary planning purposes only and do not substitute for professional engineering or architectural review.