Work out evacuation time estimate instantly with clear inputs, formula shown and shareable results.
Evacuation time is the sum of travel time to reach the exit and queuing time to pass through it. Maximum specific flow through a level opening is about 1.3 people per metre of effective width per second, so a 1.8 metre exit passes roughly 2.3 people a second. On large occupancies the queuing term dominates completely.
Flow capacity
People per second = 1.3 x effective width in metres
Total time
Time = travel distance / walking speed + occupants / flow capacity
Preliminary estimate only. Evacuation analysis for life safety design must be carried out by a qualified fire engineer, including pre-movement time and behavioural factors.
People per second = 1.3 x effective width in metres. Evacuation time is the sum of travel time to reach the exit and queuing time to pass through it.
Occupants keep a boundary layer of 150 mm from each edge of a doorway or corridor, so the effective width is less than the measured clear width and flow scales on the effective figure.
This calculator takes 4 inputs: Occupants to evacuate, Total effective exit width, Longest travel distance, Walking speed. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.