Smoke Detector Spacing Calculator

Calculate smoke detector layout and spacing requirements per NFPA 72 National Fire Alarm Code.

Higher ACH may require reduced spacing

NFPA 72 Spacing Guidelines

Ceiling Height Spacing Modifier
Up to 10 ft1.00 (no reduction)
10-12 ft0.91
12-15 ft0.84
15-18 ft0.77
18-22 ft0.71
22-26 ft0.64
26-30 ft0.58

Smoke Detection Technologies

Ionization

Best for fast, flaming fires. Detects small particles from combustion. Less effective for smoldering fires.

Photoelectric

Best for slow, smoldering fires. Uses light scatter principle. Preferred for sleeping areas and escape routes.

Aspirating (VESDA)

Very early warning. Samples air through pipe network. Ideal for data centers and high-value assets.