The capacity of means of egress stairways must be calculated by multiplying the occupant load served by such stairways by a means of egress capacity factor of ___ inch per occupant.

The capacity of means of egress stairways is a fundamental aspect of building safety, ensuring that occupants can safely evacuate in an emergency. The correct factor to use for calculating the capacity in terms of stairway width is 0.3 inches per occupant. This measurement is established by building codes to ensure that there is adequate space for individuals to exit the building efficiently, reducing congestion and the potential for injury during an evacuation.

Using this factor allows safety officials and building inspectors to determine the appropriate width of stairwells based on the expected number of occupants, thus enhancing the effectiveness of the means of egress. This guideline is crucial because it directly relates to life safety and is part of broader fire safety regulations that govern how buildings are constructed to facilitate safe evacuation.

Other options represent different capacities that are not reflective of the standard measures set forth in most building codes for commercial spaces. The distinction is essential for ensuring compliance with safety regulations and providing an effective means of egress in various building designs.