Exit Capacity

Calculate exit capacity from supplied clear widths and capacity rate.

Description

An aggregate exit-width model compares a capacity estimate with occupant load multiplied by a chosen safety factor.

An aggregate exit-width model compares a capacity estimate with occupant load multiplied by a chosen safety factor. Actual egress assessment involves more than adding widths.^[1]

Calculate exit capacity from supplied clear widths and capacity rate.

When to use Exit Capacity

Use this tool to calculate exit capacity from supplied clear widths and capacity rate.

Prepare production measurements or checklist records for one planning period. Confirm units, staffing assumptions and caller-selected criteria before running the calculation.

How to use Exit Capacity and understand its results

Prepare production measurements or checklist records for one planning period. Confirm units, staffing assumptions and caller-selected criteria before running the calculation.
Enter occupantLoad, exitWidthsMeters, capacityPerMeter, requiredSafetyFactor using the field table and calculation rules, then run the tool.
Read totalExitWidthMeters, exitCapacity, requiredCapacity, capacityMargin, adequate. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
occupantLoad	Occupant load	integer; minimum: 0	Required
exitWidthsMeters	Exit clear widths (m)	list of number	Required
capacityPerMeter	Exit capacity per meter	number; minimum: 0	Required
requiredSafetyFactor	Required capacity factor	number; minimum: 0	Required

Enter nonnegative integer occupants, nonnegative exit widths, strictly positive capacity rate and nonnegative factor. Return total width, capacity, required capacity, floored margin and inclusive adequacy flag. Empty widths are allowed.

capacity=floor(ΣwidthMeters×capacityPerMeter); required=occupants×factor; margin=floor(capacity−required)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
totalExitWidthMeters	Total exit width (m)	number; minimum: 0
exitCapacity	Calculated exit capacity	integer; minimum: 0
requiredCapacity	Required factored capacity	number; minimum: 0
capacityMargin	Exit capacity margin	integer
adequate	Capacity is adequate	boolean

json

{
  "input": {
    "occupantLoad": 200,
    "exitWidthsMeters": [
      1,
      1.5
    ],
    "capacityPerMeter": 100,
    "requiredSafetyFactor": 1
  },
  "output": {
    "totalExitWidthMeters": 2.5,
    "exitCapacity": 250,
    "requiredCapacity": 200,
    "capacityMargin": 50,
    "adequate": true
  }
}

Limitations and assumptions

No building-code values are embedded. Exit independence, travel distance, obstructions, door characteristics and legal occupancy approval are outside the model.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Breakfall Clearance: Check breakfall floor clearance against travel, reach, and buffer. For a complementary task, use Open-Flame Readiness: Audit open-flame permit and safety readiness.

References

Exit Capacity — tool.io

Similar or alternative tools

Breakfall Clearance
Check breakfall floor clearance against travel, reach, and buffer.
Open-Flame Readiness
Audit open-flame permit and safety readiness.