IBC 2024 Occupant Load
Calculator
Select the function of the space—not only an occupancy group—and enter its floor area. Every Table 1004.5 row with an occupant load factor is supported, 38 in all.
Who it's for: architects who need a quick Table 1004.5 occupant-load figure for a space, before running the full egress analysis, at schematic design or permit review.
IBC 2024 Table 1004.5 occupant load factors: square feet per person
Divide the floor area by the factor and round up to a whole occupant (§1004.5). The area basis matters: net area excludes walls, corridors and other non-occupied space; gross area is measured to the outside of the walls. Fixed seating is counted by seats (§1004.6), concentrated business use follows §1004.8, and mall buildings follow §402.8.2, so they are not in this list. This is our own grouping of the 2024 table's factors, with functions that share a factor merged into one row; the full table has more rows and notes. The 2021 table is not restated here.
| Function of space | Square feet per person | Area basis |
|---|---|---|
| Assembly standing space | 5 | net |
| Assembly with chairs only (not fixed); bowling-center areas beyond the lanes | 7 | net |
| Gaming floors | 11 | gross |
| Airport waiting areas; skating-rink and pool decks | 15 | gross |
| Assembly with tables and chairs; stages and platforms | 15 | net |
| Airport baggage claim | 20 | gross |
| Classroom areas | 20 | net |
| Exhibit galleries and museums | 30 | net |
| Day-care rooms and areas | 35 | net |
| Courtrooms outside fixed seating | 40 | net |
| Dormitories; exercise rooms; locker rooms; rink and pool surfaces | 50 | gross |
| Library reading rooms; vocational shops | 50 | net |
| Mercantile sales areas | 60 | gross |
| Industrial areas; outpatient areas; library stacks; airport concourses | 100 | gross |
| Institutional sleeping areas | 120 | gross |
| Business use floors | 150 | gross |
| Residential; parking garages; commercial kitchens; Group H-5 fabrication | 200 | gross |
| Institutional inpatient treatment areas | 240 | gross |
| Storage and mechanical rooms; agricultural buildings; IT facilities; mercantile stock areas; baggage handling | 300 | gross |
| Warehouses; aircraft hangars | 500 | gross |
Example: a 3,000 ft² gross business area at 150 gives 20 occupants; a 1,200 ft² net unconcentrated assembly area at 15 gives 80.
How to use this calculator
The formula
Worked example
When this estimate will be off
- Fixed seating (§1004.6), concentrated business use areas (§1004.8), mall buildings (§402.8.2), bowling lanes (5 persons per lane, added separately), the §1004.5 exception for an approved actual load, the §1004.5.1 increase, and local amendments are not applied.
- Mixed-function areas: calculate each function separately and add the results (§1004.3).
- Model-code result only; the locally adopted edition and any amendments are not determined.
- This is not a complete occupant-load or code-compliance determination.
Frequently asked questions
Using gross floor area for a function the table measures in net area. Assembly, classrooms, courtrooms, day care, library reading rooms, stages and educational shops use net floor area; each option in the list names its basis.
Where a function is not listed in Table 1004.5, the building official establishes the most similar listed function (§1004.5). Fixed seating (§1004.6), concentrated business use areas (§1004.8) and mall buildings (§402.8.2) have their own methods, so the calculator does not guess.
Table 1004.5 assigns the occupant-load factor by the function of the space (business area, mercantile, warehouse, etc.), which is a finer grain than the occupancy group alone.
Yes — the calculated occupant load is the floor area (gross or net, as the table row states) divided by the table factor, rounded up to the nearest whole occupant.
No. Use this occupant load as the input to the required-exits and egress-capacity calculators — this page only reports the load itself.
Business areas use 150 sq ft gross per occupant; Mercantile uses 60 sq ft gross. Assembly has no single factor — it depends on configuration: 15 sq ft net for unconcentrated tables and chairs, 7 sq ft net for concentrated chairs-only seating, 5 sq ft net for standing space, and Section 1004.6 for fixed seating.
Sources and review record
Sources and method basis
- IBC 2024 Table 1004.5: selected business, mercantile, and warehouse gross-area rows
- https://codes.iccsafe.org/
Limitations
- Supports three model-code functions only; fixed seating, mixed functions, other rows, local adoption, and amendments return cannot determine.
This free IBC 2024 Occupant Load Calculator is built and maintained by DataDrivenAEC, using the relevant codes and standards. It does not substitute for professional judgment.