Minimum corridor width?

44 in for occupant loads of 50 or more (36 in below 50).

How do I split occupants?

Distribute among exits; no single exit may lose more than half the required capacity.

When must an exit door swing out?

At 50 or more occupants under the IBC.

Maximum travel distance?

Commonly 200–250 ft unsprinklered/sprinklered for business uses; check your table.

Egress door sizing calculator

Occupants, element and code: you get the minimum clear width for an egress door, corridor or stair.

Minimum clear width

2.625 ft

Minimum clear width2.625 ft
Width from occupant load1.64 ft
Absolute minimum width2.625 ft

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How it's calculated (visible formula)

IBC: 0.2 in per occupant for doors and corridors, 0.3 in for stairs, with absolute minimums. CTE: P ÷ 200 (doors, corridors), P ÷ 160 (stairs)

Net geometric measurement, no waste.
Adjustable waste % for cuts and breakage.
Purchase rounded up to sellable units (boxes, bags, buckets, boards).

See methodology and formula versions

How to calculate it, step by step

Work out occupant load (use the occupant load calculator).
Distribute occupants among exits.
Choose the element: door, corridor or stair.
Apply the code's width per occupant.
Take the larger of the calculated and absolute minimum width.

Worked example: Door for 100 occupants under the IBC

100 × 0.2 in = 20 in
Minimum clear door width: 32 in

→ 32 in (0.81 m) clear width.

Common mistakes

Measuring the door leaf instead of clear width.
Loading all occupants onto one exit when there are several.
Forgetting stairs need more width per person.

Pro tips

With several exits, no single exit may provide more than half the capacity.
Measure clear width with the door open 90°.
Doors must swing in the direction of egress above 50 occupants.
Provide exit signs and egress lighting.

From calculation to quote

Add labour, overhead and your margin, and generate the professional PDF.

Create quote Calculate margin & GST

FAQs

Minimum egress door width?: 32 in clear in the IBC.
Minimum corridor width?: 44 in for occupant loads of 50 or more (36 in below 50).
How do I split occupants?: Distribute among exits; no single exit may lose more than half the required capacity.
When must an exit door swing out?: At 50 or more occupants under the IBC.
Maximum travel distance?: Commonly 200–250 ft unsprinklered/sprinklered for business uses; check your table.
Do escalators count as exits?: No.

Sources and standards

Maintained by Srikanta M · Formula v1.0.0 · Verified 2026-09-10 · Updated 2026-09-10 · Limits: quantity estimation, not structural design or site supervision.