What unit is used for capacity factor in egress calculations?

• A. Inches per person
• B. Feet per person
• C. Inches per square foot
• D. Centimeters per person

Answer: (A)

Capacity factor in egress calculations is about how much width each person needs to move safely through an exit. The standard way to express this is as width per person, usually in inches. This lets you turn a fixed egress width into a maximum number of people who can evacuate at once by dividing the total available width by the inches-per-person value.

For example, if a corridor is 60 inches wide and the capacity factor is 3 inches per person, you’d plan for about 20 people (60 ÷ 3 = 20) moving through that space at once.

The other options don’t fit because feet per person would imply a much larger per-person allocation than typical planning uses; inches per square foot would describe area per person (density) rather than the width-per-person measure used for capacity factor; and centimeters per person is not the standard unit in these calculations in the commonly used US codes.