Fire Water Supply Duration Calculator

Calculate required fire water supply duration based on occupancy, sprinkler system, and standpipe requirements per NFPA standards.

Input Parameters

Results

--
Required Supply Duration
minutes
--
Total System Demand
gpm
--
Water Volume Required
gallons
--
Suggested Tank Size
gallons
Note: Water supply duration must meet both sprinkler and hose stream requirements simultaneously. NFPA 13 requires the combined sprinkler demand and hose stream allowance be available for the specified duration. When a fire protection water storage tank is used, the tank must be sized for the full duration requirements plus a safety margin.

Reference

NFPA 13 Table 11.2.3.1.2 - Water Supply Duration: Light Hazard: 30 min sprinkler, 30 min hose OH Group 1: 60 min sprinkler, 60 min hose OH Group 2: 60 min sprinkler, 60 min hose EH Group 1: 90 min sprinkler, 60 min hose EH Group 2: 120 min sprinkler, 90 min hose Standpipe per NFPA 14: 30 min minimum Water Volume = (Sprinkler Flow x Duration) + (Hose Stream x Duration) Total Demand = Sprinkler + Hose Stream + Standpipe