Stairwell Capacity Calculator

Calculate stairwell capacity and evacuation time per IBC Section 1005 and NFPA 101 Chapter 7

Input Parameters

Results

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Stair Capacity
persons
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Estimated Evacuation Time
min
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Flow Rate
persons/min
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Minimum Stairs Required
Note: Stairwell capacity per IBC Section 1005 and SFPE Handbook of Fire Protection Engineering. Evacuation time is approximate - actual times depend on occupant characteristics, pre-movement time, and stair congestion.

Reference

IBC 1005.1: Stair width factor = 0.3 in/person (non-sprinklered), 0.2 in/person (sprinklered) Effective width = Clear width - 12 in (boundary layers per SFPE) Flow rate Fs = 18.5 persons/min/ft effective width (SFPE Handbook) Stair descent speed ~1.0 ft/s Min 2 exits required per IBC 1021.1