National Fire Academy Quick Fire-Flow
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.
Formula and source
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.
Audience
This tile is built for fire-ground and the adjacent professions in the Fire-Ground Engineering group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
Related tools
Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.