Venue Occupancy & Exit Width

Estimate how many people a venue can hold from its floor area and use, then check the exits against UK (Approved Document B / BS 9999) or US (IBC / NFPA 101) guidance.

Planning aid only. The real capacity is set by the fire risk assessment and by the licensing or building authority. This tool doesn't replace the regulations, a fire risk assessment or the judgement of a competent person.

Region & Method

Region
Units
Minimum fire protection measures. BS 9999 allows lower figures where extra measures are fitted, but never below the floor value for the profile.
min
The fire risk assessment decides the evacuation time. The Green Guide uses 2.5 minutes for high fire risk and up to 8 minutes for low risk.

Step 1 — Occupancy from Floor Space

Zone Use Area / quantity People
Floor-space capacity
—

Each zone is rounded down to whole people. Seated areas are counted by seats: ADB allows the number of fixed seats where people will normally be seated, and IBC 1004.6 uses the seat count, 18 in of bench or 24 in of booth per person.

Step 2 — Exits

Enter the clear width of each exit: for a door, measured with the door open, from the stop to the leaf or to any projecting ironmongery. Only list exits that are separate, independent routes to a place of safety.

Exit Clear width Type Main Capacity
Total clear width
—
After discounting largest
—
Usable exits
0
Exit capacity
—
Exits needed for floor-space capacity
—
Width needed for floor-space capacity
—

Capacity Summary

people
Capacity
—
Floor space
—
Exits
—
Licence cap
—
Basis

    Other things can lower capacity further: travel distances, stair widths, gangways and seating layout, accessible refuges, sanitary provision, and stewarding and crowd management. This tool doesn't check any of them.

    Notes & References

    • Approved Document B, Volume 2 (buildings other than dwellings), 2019 edition incorporating the 2020 and 2022 amendments (England). Floor space factors: Appendix D, Table D1. Number of exits: Table 2.2 (up to 60 people → 1, up to 600 → 2, over 600 → 3). Exit widths: Table 2.3 (60 → 750 mm, 110 → 850 mm, 220 → 1,050 mm, over 220 → 5 mm per person, with no interpolation below 1,050 mm). Discounting the largest storey exit: para 2.21. Adding exit capacities together: para 2.22. Width measurement: Appendix D, Diagram D1.
    • BS 9999:2017 Fire safety in the design, management and use of buildings. The risk profile is the occupancy characteristic (A awake and familiar, B awake and unfamiliar, C sleeping) plus the fire growth rate (1 slow to 3 fast). Profiles ending in 4 (ultra-fast) are not applicable. The widths per person here are the minimum-measures values from secondary summaries of the standard, so check them against your copy. BS 9999 stair widths depend on the number of floors served and are not calculated here.
    • Outdoor events: the Guide to Safety at Sports Grounds (Green Guide), 6th edition, 2018, uses a rate of passage of 82 people per metre per minute on level surfaces and 66 on stepped surfaces. Its emergency evacuation time is 2.5 minutes for high fire risk and up to 8 minutes for low risk. HM Government's Fire Safety Risk Assessment: Open Air Events and Venues (2006) uses 109 and 73. The Event Safety Guide (HSG195) refers to the Green Guide for exit widths and notes that 0.5 m² per person is generally used for outdoor music events. The Purple Guide (Events Industry Forum) gives current outdoor event guidance.
    • Scotland and Northern Ireland have their own rules. Scotland uses the Building Standards Technical Handbook (Non-domestic), Section 2 Fire, clause 2.9, with its own occupancy capacity table and exit widths. Northern Ireland uses Technical Booklet E. Wales has its own version of Approved Document B.
    • International Building Code 2021 (the 2024 figures used here are unchanged). Occupant load factors: Table 1004.5. Fixed seating: 1004.6. Egress width: 1005.3.1 (stairways 0.3 in per occupant) and 1005.3.2 (other components 0.2 in), reduced to 0.2 in and 0.15 in where the building is sprinklered with emergency voice/alarm communication (not Group H or I-2). Spaces with one exit: Table 1006.2.1 (Group A: 49). Three or four exits: 1006.2.1.1 and Table 1006.3.3 (1–500 → 2, 501–1,000 → 3, over 1,000 → 4). Door clear width: 32 in minimum (1010.1.1). Assembly main exit: 1030.2 (over 300 occupants, at least half the load); other exits: 1030.3.
    • NFPA 101 Life Safety Code. Occupant load factors: Table 7.3.1.2. Capacity factors: Table 7.3.3.1 (stairs 0.3 in, level components and ramps 0.2 in per person). Main entrance/exit: 12.2.3.6 (half the load, or two-thirds for dance halls, discotheques, nightclubs and festival seating). Number of means of egress: 12.2.4 (over 500 → 3, over 1,000 → 4). New door openings: 32 in minimum clear width. These NFPA figures come from published summaries of recent editions, so confirm them against the edition your jurisdiction has adopted.
    • Local amendments vary from state to state and city to city. The Authority Having Jurisdiction (AHJ) and the fire marshal set the posted occupant load.

    This is guidance and a planning aid. It doesn't replace the regulations, a fire risk assessment, the licensing or building authority, or the judgement of a competent person.