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Sprinkler coverage calculator

Estimate the number of sprinkler heads a floor needs by hazard class and coverage per head — a planning aid ahead of a full AS 2118.1 hydraulic design.

The area
Floor area to protect and the hazard class.
Sprinkler heads needed
29
For 600 m² at 21 m² max coverage per head — with a maximum head spacing of 4.6 m for light hazard.
Max coverage per head21 m²
Max head spacing4.6 m
Heads required29

Indicative only. Sprinkler design under AS 2118.1 also covers hydraulic calculations, water supply, head type and spacing rules — the number of heads alone doesn’t make a compliant system.

traqR keeps sprinkler systems, block plans and AS 1851 service records against each site so your inspections stay on track.

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How it works

1

Set the hazard

The fire load of the occupancy — light, ordinary or high hazard — determines how much floor each sprinkler head can protect.

2

Divide the area

Dividing the floor area by the maximum coverage per head, and rounding up, gives an indicative head count.

3

Then hydraulically design

Head count is only the start. AS 2118.1 requires hydraulic design, water supply verification and correct spacing before a system is compliant.

Frequently asked questions

How many sprinkler heads do I need?

It depends on the floor area and the hazard classification, which sets the maximum area each head can cover — commonly around 21 m² for light hazard, 12 m² for ordinary hazard and less for high hazard. This tool divides area by that coverage, but a real design also fixes head spacing and hydraulics.

What is hazard classification?

Sprinkler standards group occupancies by their fire load and how fast a fire could grow — light, ordinary and high (or extra) hazard. Higher hazards need denser sprinkler coverage and more water. Getting the classification right is fundamental to the design.

Does coverage area alone size a system?

No. A sprinkler system must also be hydraulically designed so every head in the design area gets enough flow and pressure, with an adequate and reliable water supply. AS 2118.1 covers all of this — head count is just one input.

Is this calculator compliant with AS 2118?

No. It’s an indicative planning aid. Sprinkler systems must be designed, installed and certified by qualified fire protection designers to AS 2118.1, with maintenance to AS 1851.

This calculator is an indicative aid using typical coverage figures, not a substitute for AS 2118.1. Compliant sprinkler design requires hydraulic calculation, water supply verification, correct head selection and spacing, carried out by qualified designers, with maintenance to AS 1851.

Keep sprinkler servicing on track

traqR keeps sprinkler systems, block plans and AS 1851 records against each site. Try it free for 14 days.

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