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Calcimator

Fire Alarm Coverage Calculator

Calculate detector count and spacing per NFPA 72 for smoke and heat detectors.

Inputs

Results

Detectors Required

3

Adjusted Spacing (ft)

30

Coverage per Detector (sq ft)900
Height Adjustment Factor1
Estimated Total Cost$360.00
Cost per Sq Ft$0.18
Base Spacing30
How to Use This Calculator
  1. Enter Room Area (sq ft), Ceiling Height (ft), and Ceiling Type.
  2. Set Detector Type.
  3. Review Detectors Required and Adjusted Spacing (ft).
  4. Use Coverage per Detector (sq ft) and Height Adjustment Factor to inform your decision.

How the result changes with Room Area (sq ft)

Room Area (sq ft)Detectors RequiredAdjusted Spacing (ft)
10,0451230
35,0333930
65,0187330
90,00510130

What each input means

Room Area (sq ft)
Total floor area requiring detector coverage.
Ceiling Height (ft)
Height from floor to ceiling.
Ceiling Type
1=Flat/Smooth, 2=Beamed, 3=Sloped.
Detector Type
1=Smoke Detector, 2=Heat Detector.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Room Area (sq ft) = 2000, Ceiling Height (ft) = 10, Ceiling Type = 1, Detector Type = 1 = 4 input(s) provided
  2. Calculate Detectors Required
    Detectors Required
    3 = 3
  3. Calculate Adjusted Spacing
    Adjusted Spacing
    30 = 30
  4. Calculate Coverage per Detector
    Coverage per Detector
    900 = 900
  5. Calculate Height Adjustment Factor
    Height Adjustment Factor
    1 = 1

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