California Building Code Occupancy Load Table 1004.5

The California Building Code occupancy load table, Table 1004.5 in Chapter 10 of the 2025 California Building Code (Title 24, Part 2), assigns every type of usable space a factor in square feet per person. Divide the floor area by that factor, round up, and you have the occupant load the space is legally designed to hold. That number then controls how many exits the space needs, how wide its doors and corridors must be, and which direction its doors swing. The 2025 edition took effect January 1, 2026.

The Formula and the Rounding Rule

For any space without fixed seating, the occupant load equals the floor area divided by the occupant load factor in Table 1004.5. The code says the result “shall be not less than” that number, so fractions always round up. A 3,200-square-foot office divided by 150 gives 21.3, and the load is 22.

You run the calculation separately for each distinct functional area, then add the results. A floor containing a classroom, a storage closet, and a corridor produces three subtotals, and the sum is what drives the building’s egress requirements. Skipping a secondary area, like a lobby or a waiting zone, is one of the most common mistakes people make.

Gross Floor Area Versus Net Floor Area

Table 1004.5 tells you whether each use is calculated on gross or net area, and the two produce meaningfully different numbers. Gross area for a given room can run 15 to 25 percent larger than net area for the same room.

Gross floor area covers everything inside the exterior walls, including interior partitions, restrooms, mechanical closets, and columns. You measure wall to wall and subtract nothing.
Net floor area counts only the space actually available to occupants. Walls, columns, fixed equipment, restrooms, closets, and mechanical areas come out.

Each row of the table is marked “gross” or “net” next to the factor. Business areas use gross; assembly spaces with chairs use net. Applying net to a gross-area use inflates the occupant count and may push you into extra exits or wider corridors you don’t actually need. Applying gross to a net-area use undercounts occupants, which is the dangerous direction of the error.

The Factors You’ll Use Most

A lower factor means a denser space. A higher factor means people are spread out. California adopts the IBC table with state amendments.

Assembly

Standing space: 5 net square feet per person
Concentrated seating, chairs only and not fixed: 7 net
Unconcentrated, tables and chairs: 15 net
Gaming floors: 11 gross
Exhibit galleries and museums: 30 net
Stages and platforms: 15 net

A 2,000-square-foot banquet hall set with tables and chairs holds 134 (2,000 ÷ 15 = 133.3, rounded up). Rearrange the same room for a standing reception and the load jumps to 400.¹

Business, Educational, and Industrial

Business areas (offices): 150 gross square feet per person
Educational classrooms: 20 net
Vocational shops: 50 net
Industrial areas: 100 gross
Day care: 35 net

Classrooms pack more people into less space than offices. A 600-square-foot classroom carries a load of 30; the same 600 square feet of office counts as 4.¹

Mercantile, Residential, and Storage

Mercantile (retail sales floors): 60 gross square feet per person
Residential: 200 gross
Dormitories: 50 gross
Commercial kitchens: 200 gross
Storage, stock, and shipping areas: 300 gross
Accessory storage and mechanical equipment rooms: 300 gross
Warehouses: 500 gross

Warehouses and mechanical rooms carry the highest factors because very few people occupy that square footage. A 15,000-square-foot warehouse produces an occupant load of only 30.¹

Fixed Seating and Mixed-Use Spaces

The table-based formula does not apply where seating is fixed. Theaters, auditoriums, lecture halls, and stadiums are calculated by counting the actual installed seats. Continuous seating without dividing arms, such as pews and bleachers, counts one person for every 18 inches of seating length. Restaurant booths use one person for every 24 inches.

Most real buildings mix uses on a single floor, and this is where calculations go wrong. A restaurant with a fixed-booth section and an open dining area needs two calculations: the booths by seating length, the open dining area at 15 net square feet per person. Add the two together for the space’s total load.

Going Above the Table Number

The table produces a floor, not a ceiling. The code allows an increased occupant load if every other requirement, including exits, fire protection, and plumbing fixtures, is sized for the higher number, and the load never exceeds one person per 7 square feet of occupiable floor space. The fire code official can require a seating or equipment diagram to confirm the layout supports the increase.²

This comes up most with event venues and restaurants reconfiguring for different functions. A banquet hall designed for 200 seated guests can host a 350-person standing reception, but only if the exits, corridor widths, and fire suppression have been designed around 350.

What the Occupant Load Controls

The number you calculate feeds directly into three egress decisions.

How Many Exits

Most spaces with an occupant load above 49 need at least two exits. Below that threshold, some occupancies (including business, educational, and mercantile) can work with a single exit if they meet travel-distance limits. At the story level the minimums scale with total load: two exits up to 500 occupants, three for 501 to 1,000, four above 1,000.

How Wide the Exits Must Be

Each egress component’s required width equals the occupant load it serves times a capacity factor. Corridors, doorways, ramps, and other non-stair components use 0.2 inches per occupant. Stairways use 0.3 inches per occupant, reflecting slower movement on stairs. Both factors can be reduced in buildings equipped throughout with automatic sprinklers and an emergency voice/alarm system.³

So a corridor serving 200 occupants needs at least 40 inches clear (200 × 0.2). A stairway serving the same 200 needs 60 (200 × 0.3). The code also sets absolute minimum widths that may control when the occupant load is low.

Which Way the Door Swings

Doors serving a room with an occupant load of 50 or more must swing in the direction of exit travel, typically outward. That prevents a crowd from pressing against the door and trapping people behind it. Rooms below 50 are generally allowed to swing inward, though high-hazard occupancies always require outward swing regardless of load.⁴

Posting and Overcrowding

Assembly occupancies are generally required to post a sign near the main exit showing the maximum occupant load approved by the fire code official. The California Fire Code defines overcrowding as exceeding the posted or authorized capacity, or allowing people to sit or stand in locations that block aisles, corridors, stairways, or exits. Both are prohibited, and the fire code official has authority to enforce compliance.⁵

Enforcement runs from a written notice to correct conditions up to an order to immediately reduce occupants or vacate the building. Owners and event managers are responsible for monitoring actual attendance against the posted capacity, especially in venues with fluctuating turnout like bars, nightclubs, and banquet halls. The number you pull from Table 1004.5 is the number you remain accountable for every time the doors open.⁶

1
ICC Digital Codes. 2024 International Building Code – Chapter 10 Means of Egress
2
UpCodes. California Fire Code 2025 – Chapter 10 Means of Egress
3
ICC Digital Codes. 2021 International Building Code – Chapter 10 Means of Egress
4
UpCodes. California Building Code 2022 – Chapter 10 Means of Egress
5
UpCodes. Overcrowding, 24-Hour Care
6
Cornell Law Institute. California Code of Regulations Title 19 3.27 – Overcrowding