Required clear width = occupant load × capacity factor (IBC 1005), compared against the dimensional minimum (IBC 1010 / 1020) — the larger governs.
Factors: IBC 2021. Reduced factors apply only where the building is sprinklered (903.3.1.1/.2) AND emergency voice/alarm (907.5.2.2).
Egress width has two independent tests: the IBC 1005 capacity calculation (occupant load × a per-occupant factor) and the dimensional minimum for the component (e.g., a 32″ clear door, a 44″ corridor). The required width is the larger of the two. A component that meets the dimensional minimum can still fail when its occupant load demands more capacity. For the full interaction, see our corridor & door width guide.
Check your full plan set →This calculator uses model IBC factors for general reference. It is not a substitute for the adopted code and amendments enforced by your local authority having jurisdiction. Always verify against the edition and amendments your jurisdiction has adopted.