Evacuation Time Estimate Calculator for Construction Sites

Calculator Inputs

For multi-level sites, include floors and stair run length.

People to evacuate

Count in the affected zone (not the entire site).

Corridor distance to exit (m)

Average horizontal distance to the discharge point.

Floors to descend

Use 0 for single-level evacuation.

Stair run per floor (m)

Typical temporary stair travel per level (run).

Walking speed (m/s)

Common planning range: 0.8–1.5 m/s.

Stair speed (m/s)

Down-stairs is often slower than corridor travel.

Pre-movement time (minutes)

Recognition + response delay before movement begins.

Exit width (each) (m)

Use clear usable width, not frame-to-frame.

Number of exits

Only count exits that can be used simultaneously.

Specific flow (persons per meter per second)

Typical planning: 1.0–1.6, depending on conditions.

Route factor (multiplier)

Turns, obstacles, lighting, signage, uneven ground.

Safety factor (%)

Adds buffer for variability and uncertainty.

Reset

Example Data Table

Sample scenarios for quick benchmarking and drills.

Scenario	People	Distance (m)	Floors	Exit width (m)	Exits	Pre-move (min)	Route factor
Ground-level muster	40	30	0	1.2	1	0.3	1.05
Two floors, temporary stairs	80	45	2	1.2	1	0.5	1.10
High-occupancy zone with two exits	160	55	3	1.4	2	0.7	1.20
Congested route and delays	120	70	4	1.0	1	1.2	1.40

Formula Used

A practical planning model combining travel, discharge, and delays.

1) Corridor travel time

t_corridor = D / v

2) Stair travel time

t_stair = (F × S) / v_s

3) Route-adjusted travel time

t_travel = (t_corridor + t_stair) × R_f

4) Exit discharge capacity and service time

C = W × E × q (persons/second)

t_service = N / C

5) Movement core (conservative)

t_core = max(t_travel, t_service)

6) Total evacuation estimate

t_total = (t_pre + t_core) × (1 + S_f)

Symbols: N people, D corridor distance, v corridor speed, F floors, S stair run per floor, v_s stair speed, R_f route factor, W exit width, E exits, q specific flow, t_pre pre-movement seconds, S_f safety factor fraction.

How to Use This Calculator

Steps for consistent, repeatable site estimates.

Enter the people count for the affected work zone.
Estimate average corridor distance to the discharge point.
Add floors to descend and stair run per floor.
Use realistic walking and stair speeds for your crew mix.
Include pre-movement time for response and regrouping.
Set exit width and number of exits usable together.
Adjust specific flow for wet surfaces or debris.
Use route factor to capture turns and obstacles.
Add a safety factor to reflect uncertainty.
Submit and review the breakdown, then export CSV or PDF.

Use results to improve routes, signage, drills, and training.

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