Evacuation Time Estimate Calculator

Work out evacuation time estimate instantly with clear inputs, formula shown and shareable results.

About Evacuation Time Estimate Calculator

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.

Formulas

Flow capacity

People per second = 1.3 x effective width in metres

Total time

Time = travel distance / walking speed + occupants / flow capacity

Worked example

With the default values below, Evacuation Time Estimate Calculator returns Estimated evacuation time of 2.69. Change any input above and every figure here is recalculated in your browser.

Inputs used

Occupants to evacuateminimum 1 people: 300 people
Total effective exit widthminimum 100 mm: 1,800 mm
Longest travel distanceminimum 1 m: 40 m
Walking speedminimum 0.2 m/s: 1.2 m/s

Results

Estimated evacuation time: 2.69 min
Travel time to the exit: 33.3 s
Queuing time through the exit: 128.2 s
Exit flow capacity: 2.340 people/s

Step by step

1Values used
2Flow capacity
3Total time
4Estimated evacuation time= 2.69 min
5Travel time to the exit= 33.3 s
6Queuing time through the exit= 128.2 s
7Exit flow capacity= 2.340 people/s

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
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.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

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.

Frequently Asked Questions

How is the Evacuation Time Estimate figure worked out?

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.

Why does effective width matter rather than clear width?

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.

What values do I need to enter?

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.