Engine Ops Tool
Needed Fire Flow (NFF) + Attack Line Planner
Fast NFF estimates (NFA / Iowa / ISO simplified) + instant “how many lines?” planning for first-arriving companies.
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Building Inputs
NFF Estimate
Enter dimensions and calculate.
Needed Fire Flow
0
GPM
Attack / Backup Suggestion
—
Attack: 0Backup: 0
Water Needed (rough)
Estimated total gallons for selected duration.
0
gallons
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Fire Flow Calculator (NFF): Quick Estimate + Line Planning
Use this calculator for quick operational estimates and training. Always follow local SOP/SOG, hydrant test records, and water department data when available.
Methods included
- NFA Field: (L×W)/3 × floors × involvement%
- Iowa: (L×W×H)/100 × involvement%
- ISO Simplified: C=18×F×√A, then NFF=C×O×(1+(X+P))
Line planner output
- Attack lines needed at chosen target GPM
- Backup recommendation (ratio-based)
- Total gallons estimate for a chosen duration
Worked Example
Example (NFA): L=50ft, W=75ft, floors=1, involvement=100%
NFF ≈ 1250 GPM (then plan lines based on your target line flow).
Fire Flow (NFF) FAQ
Needed Fire Flow (NFF) is a quick estimate of how much water (GPM) may be required to control a fire in a building or area. It’s commonly used for training, first-arriving water supply planning, and pre-incident considerations.
For quick ops estimates, many crews use a simple field formula like NFA. Iowa emphasizes volume (L×W×H). ISO methods often include construction/occupancy and exposure factors. Use the method your department’s SOP/SOG recommends.
It’s a quick operational slider. If only part of the building/area is involved, reducing the percentage can give a rough adjusted estimate. Real-world needs still depend on fire behavior, compartmentation, exposures, and tactics.
This tool provides estimates for training and rapid planning. Actual required flow depends on building features, ventilation, fire load, exposures, water system conditions, and your tactics. Always follow local SOP/SOG and preplan data.
The planner converts the estimated NFF into a simple “how many lines could meet this” view, using your selected target GPM per line and a backup ratio. It’s not a replacement for company officer judgment—just a quick starting point.
Yes. After you estimate NFF here, use the Hydrant Flow Calculator to estimate available hydrant GPM from pitot readings (and see NFPA 291 color class).
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