National Fire Academy Quick Fire-Flow
The fireground size-up quick-calc: NFF = (L x W / 3) x (percent involved / 100) x floors.
Example
You enter
- Building length (ft) 40
- Building width (ft) 60
- Percent involved (%) 50
- Involved floors 1
- Exposures to protect 2
You get
- Base fire flow 400 gpm
- Exposure (GPM) 200
- Total (GPM) 600
Details, formula, and sources
The fireground size-up quick-calc: NFF = (L x W / 3) x (percent involved / 100) x floors, plus 25% of the base per exposure. Validated only for interior/offensive attack up to ~50% involvement and ~1,000 gpm -- beyond that it under-predicts and the fight is defensive (use the ISO required-fire-flow method). A mental scene-size-up tool, not a water-supply design.
base = (length x width / 3) x (percent_involved / 100) x floors_involved; exposure = 0.25 x base per exposure; total = base + exposure; valid when percent_involved <= 50 and base <= 1000 gpm.
National Fire Academy fireground fire-flow quick-calc (NFA; IFSTA), by name.
The NFA quick-calc is public fire-service training material; incident command governs the actual attack.
Estimate. AHJ and licensed fire protection engineer govern.
Field names used by the API: length_ft, width_ft, percent_involved, floors_involved, exposures, base_gpm, exposure_gpm, total_gpm
- Validity envelope interior/offensive attack, <= 50% involvement, <= ~1,000 gpm base; outside it the fire is defensiveNational Fire Academy
- Additions 0.25 x base per exposure; multiply the base by the number of involved floorsNFA / IFSTA