Egress Width Calculator
Calculate IBC capacity width from the occupant load served, or estimate how many occupants an existing clear width can support.
Use the Egress Width Calculator
IBC Capacity Inputs
Use the load served by this component—not an assumed equal share.
Enter the occupant load to calculate capacity width.
Capacity width required
IBC capacity factors
| Component | Standard | Reduced* |
|---|---|---|
| Stairway | 0.30 in/person | 0.20 in/person |
| Other component | 0.20 in/person | 0.15 in/person |
*Requires every condition in IBC 1005.3.1 or 1005.3.2. Source: 2024 IBC Chapter 10 (ICC).
Capacity is not the dimensional minimum
Verify the adopted edition and dimensional rules separately. Door clear width is generally 32 in with exceptions; corridor values in Table 1020.3 vary by occupancy and load; stair widths and exceptions require a separate check.
This screening does not determine exit count, remoteness, distribution, convergence, travel distance, accessibility, hardware or complete compliance. Final design requires the local authority having jurisdiction and a qualified code professional.
Privacy: calculations run locally in your browser; values are not submitted by this tool.
Summary
Calculate IBC capacity width from the occupant load served, or estimate how many occupants an existing clear width can support.
How it works
- Enter the occupant load served by the component being checked.
- Choose a stairway or another egress component.
- Use the standard factor unless every reduced-factor condition is satisfied.
- Optionally enter an existing clear width to compare its capacity with the load.
- Verify dimensional minimums, local amendments and the complete design with the authority having jurisdiction.
Use cases
- Screen aggregate stairway capacity during early design.
- Estimate door, corridor, aisle or ramp capacity.
- Check occupant capacity represented by an existing clear width.
- Compare standard and conditionally reduced IBC capacity factors.