Fire Flow Calculator
Estimate the required fire flow rate (GPM) for a building based on floor area and construction type.
Formula
Q = 18 × C × √(A) GPM (NFF method)
- C = construction coefficient: wood 1.5, masonry 1.0, fire-resistive 0.6.
- This is a simplified estimate; consult your local fire code and AHJ.
- Maximum fire flow: typically 12,000 GPM per code.
5000 sq ft, wood frame, 1 story
Inputs
- Building Floor Area: 5000 sq ft
- Number of Stories: 1
- Construction Type: wood
Q = 18 × 1.5 × √5000 = 18 × 1.5 × 70.7 ≈ 1,909 GPM.
Frequently asked questions
Who determines required fire flow?
The local Authority Having Jurisdiction (AHJ), usually the fire department or building official.