Fire Sprinkler Design Calculator
Calculate sprinkler head count, spacing, design density, and pipe sizing per NFPA 13.
Inputs
Results
Sprinkler Heads Required
39
Total Design Flow (GPM)
750
Design Density (gpm/sq ft)0.15
Max Head Spacing (ft)15
Recommended Pipe Size (in)3
Remote Design Area (sq ft)1,500
Remote Area Flow (GPM)225
How to Use This Calculator
- Enter Hazard Classification, Protected Area (sq ft), and Ceiling Height (ft).
- Review Sprinkler Heads Required and Total Design Flow (GPM).
- Use Design Density (gpm/sq ft) and Max Head Spacing (ft) to inform your decision.
How the result changes with Protected Area (sq ft)
| Protected Area (sq ft) | Sprinkler Heads Required | Total Design Flow (GPM) |
|---|---|---|
| 50,090 | 386 | 7,513.5 |
| 175,065 | 1,347 | 26,259.8 |
| 325,035 | 2,501 | 48,755.3 |
| 450,010 | 3,462 | 67,501.5 |
What each input means
- Hazard Classification
- 1=Light, 2=Ordinary-1, 3=Ordinary-2, 4=Extra-1, 5=Extra-2.
- Protected Area (sq ft)
- Total floor area requiring sprinkler coverage.
- Ceiling Height (ft)
- Height from floor to ceiling or roof deck.
How this is calculated
Worked example, using the default values
- Identify Input ParametersHazard Classification = 2, Protected Area (sq ft) = 5000, Ceiling Height (ft) = 10 = 3 input(s) provided
- Calculate Sprinkler Heads RequiredSprinkler Heads Required39 = 39
- Calculate Total Design FlowTotal Design Flow750 = 750
- Calculate Design DensityDesign Density0.15 = 0.15
- Calculate Max Head Spacing15 = 15
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