Fire Flow Calculator
Calculate Required Fire Flow (RFF) for fire suppression using NFA or ISU/IOWA methods
Calculate Required Fire Flow
CRITICAL SAFETY NOTICE
Fire flow calculations are critical for public safety and firefighting operations. These calculations should only be used by qualified fire protection engineers, firefighters, or trained professionals. Always consult with local fire departments and follow applicable fire codes and regulations. Inadequate fire flow can result in loss of life and property.
RFF = (L × W / 3) × Floors
Most commonly used method
RFF = Volume / 100
Volume-based calculation
Longest dimension of the building
Width perpendicular to length
Number of floors actively burning
Percentage of building currently involved in fire
Additional floors exposed to fire (max 5)
Surrounding structures at risk
Required Fire Flow Results
Method: National Fire Academy (NFA)
Building dimensions: 0.0' × 0.0'
Building area: 0 sq ft
Base fire flow: 0 GPM
Fire involvement: 100% (0 GPM)
Total exposures: 0 (+0%)
Example Calculation
Single-Story Commercial Building
Building: 20 ft × 20 ft single-story warehouse
Method: National Fire Academy (NFA)
Fire involvement: 100% (fully involved)
Exposures: None
NFA Method Calculation
RFF = (Length × Width / 3) × Floors
RFF = (20 × 20 / 3) × 1
RFF = (400 / 3) × 1
RFF = 133 GPM
Fire Hydrant Standards
Minimum Flow
500 GPM minimum
Basic fire hydrant requirement
Standard Flow
1,000-1,500 GPM
Typical urban hydrant capacity
Maximum Flow
12,000 GPM maximum
Single fire event limit
Fire Flow Guidelines
Always consult local fire codes and regulations
Consider water supply availability and pressure
Account for building construction and contents
Multiple exposures increase flow requirements
Coordinate with fire department capabilities
Understanding Fire Flow Calculations
What is Fire Flow?
Fire flow refers to the amount of water required to suppress or control a fire effectively. It represents the flow rate of water, typically measured in gallons per minute (GPM), that needs to be delivered to the fire scene for successful firefighting operations.
Why is it Critical?
- •Ensures adequate water supply for fire suppression
- •Prevents firefighter safety hazards from insufficient water
- •Protects surrounding structures from fire spread
- •Enables strategic firefighting attack planning
Calculation Methods
National Fire Academy (NFA)
RFF = (L × W / 3) × F
- L: Building length (feet)
- W: Building width (feet)
- F: Number of floors on fire
Iowa State University (ISU)
RFF = (L × W × H) / 100
- L: Building length (feet)
- W: Building width (feet)
- H: Building height (feet)
Professional Consultation Required
Fire flow calculations are estimates and should always be verified by qualified fire protection engineers. Local fire codes, building construction, occupancy types, and available water systems must all be considered. Contact your local fire department and fire protection professionals for accurate assessments.