Sprinkler hydraulics calculator

Calculate fire protection flow requirements per NFPA 13

Try it now

Live calculator

Live preview

Loading calculator...

The Sprinkler Hydraulics Calculator helps fire protection engineers determine water flow requirements for sprinkler systems according to NFPA 13 standards. Calculate required flow rates based on hazard classification and design area.

Proper sprinkler system design ensures adequate water supply to control or suppress fires. NFPA 13 specifies minimum water densities (gpm per square foot) for different hazard classifications, from light hazard occupancies to extra hazard industrial facilities.

Enter hazard classification and design area to calculate required flow rate in GPM. The calculator uses NFPA 13 density requirements and helps size water supply systems, pumps, and piping for fire protection installations.

Features

Everything you need

NFPA 13 density requirements
Hazard classification support
Flow rate calculations
Design area inputs
Multiple hazard group support
Water supply sizing
Imperial and metric units

How it works

Simple workflow

1
Select hazard classification
2
Enter design area
3
Review calculated density requirement
4
See required flow rate in GPM
5
Size water supply accordingly

Use cases

Built for real-world scenarios

Fire protection design

Determine water supply requirements for new sprinkler system installations.

Code compliance

Verify sprinkler systems meet NFPA 13 density and flow requirements.

Water supply sizing

Size water supply systems, pumps, and storage tanks for fire protection.

System upgrades

Evaluate existing system capacity when changing occupancy or hazard classification.

FAQ

Frequently asked questions

NFPA 13 densities: Light Hazard 0.1 gpm/ft², Ordinary Group 1 0.15 gpm/ft², Ordinary Group 2 0.20 gpm/ft², Extra Hazard 1 0.30 gpm/ft², Extra Hazard 2 0.40 gpm/ft². Higher densities for higher hazard.

Design area is the maximum area of sprinkler operation expected during a fire, typically 1,500-3,000 ft² depending on hazard. NFPA 13 specifies minimum design areas for each hazard classification.

Required Flow = Design Area × Density. For Light Hazard with 1,500 ft² design area: Flow = 1,500 × 0.1 = 150 GPM minimum.

Hazard classification (occupancy type and materials), ceiling height, building construction, and special hazards. Higher hazards require higher densities and larger design areas.

Have a suggestion?

We're always looking to improve our calculators. If you have ideas for new features, improvements, or found something that could work better, we'd love to hear from you.

Related tools