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Fire Protection System Calculator

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Input Data
Enter your project data
Select fire protection system type to design
Duty + standby (each 100 %) + jockey. Driver choice depends on power-supply reliability, not pressure
A diesel standby may need a pressure relief valve (NFPA 20 §4.20.1.2) — see the Fire Pump Room calculator
Safety margin added to the required pressure to get the pump rated pressure. Same default (10 %) as the Fire Pump Room calculator.
Applicable standard for fire cabinet/hydrant system
Fire cabinet system installation type
Standard fire hose length
Inner diameter of fire hose
Nozzle type affects K-factor and pattern
Vertical riser height from pump to highest outlet
Number of hoses operating simultaneously
For labeling only — all hydrant values below are entered manually, not looked up from a table
Leave 0 if there are no exterior/yard hydrants on this pump. Verify the required simultaneous count against your code.
Design flow per hydrant outlet — verify against your applicable standard (typical range varies widely by code and hazard)
Minimum pressure required at the hydrant outlet while flowing — verify against your applicable standard
Pipe run length from pump to the farthest hydrant on the yard main, for friction loss
Maximum distance between adjacent hydrants around the site/building perimeter — informational, for the report; verify against your applicable code
How long the hydrant flow must be stored. Typical: NFPA 24 / NFPA 1 fire flow 120 min, KMK 2.04.02 / SNiP 180 min; up to 180 min where the fire station is far or the risk is high. A changed value is marked as user input in the report.
Applicable code family — each hazard area below is looked up against this standard
Total floor area protected as Light Hazard. Leave 0 if not present in this project.
Vertical distance from pump to this area's highest sprinkler
Total floor area protected as Ordinary Hazard. Leave 0 if not present in this project.
NFPA 13: OH1 6.1 mm/min (car parks, bakeries, laundries), OH2 8.1 mm/min (mercantile, machine shops, repair garages) — design area 139 m². EN 12845: all OH groups 5.0 mm/min; area of operation OH1 72, OH2 144, OH3 216, OH4 360 m². OH3 / OH4 exist in EN 12845 only.
Vertical distance from pump to this area's highest sprinkler
Total floor area protected as Extra Hazard. Leave 0 if not present in this project.
NFPA 13: EH1 12.2 mm/min (aircraft hangars, saw mills, die casting), EH2 16.3 mm/min (flammable liquid spraying, plastics manufacturing) — design area 232 m². EN 12845 high hazard process: HHP1 7.5, HHP2 10.0, HHP3 12.5 mm/min — area of operation 260 m².
Vertical distance from pump to this area's highest sprinkler
NFPA 13 §11.2.3.2.5: dry pipe and double-interlock preaction → design area +30 %. Table 22.4.4.7: black steel C=120 wet, C=100 dry/preaction.
NFPA 13 §11.2.3.1.3: the lower water-supply durations (OH 60 / EH 90 min instead of 90 / 120) are only permitted when alarm and supervisory devices are monitored at a constantly attended location
Sprinkler head type and orientation
Length of the feed main from the pump to the most remote design area, plus the equivalent length of its fittings (elbows, tees, valves). Losses inside the design area are added automatically.
Pressure loss through the installation valve set at the design flow - take it from the valve manufacturer's data
Sprinkler pipe material for friction calculation
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Calculation Results
Calculated instantly from your inputs
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Fire Protection System Calculator

Complete fire protection system design calculator.

FIRE CABINET & HYDRANT MODE:
• NFPA 14, EN 671-1/2, TS 9251/12183 compliance
• Hose friction loss and riser sizing
• Pump pressure requirement
• Manifold/header sizing

AUTOMATIC SPRINKLER MODE:
• NFPA 13, EN 12845, TS EN 12845 compliance
• Sprinkler count and placement
• Pipe sizing (main and branch)
• Hydraulic calculations
• Tank volume (NFPA 22 / EN 12845)
• Pump selection

PUMP SELECTION:
• Duty + standby (each 100 %) + jockey
• NFPA 20 standard rating (Table 4.28(b))
• Electric or diesel driver per pump

STANDARDS SUPPORTED:
• NFPA 13, 14, 20, 22
• EN 12845, 671-1/2
• TS 9251, TS EN 12845, TS 12183

DESIGN DENSITIES:
Light Hazard: EN 2.25 / NFPA 4.1 mm/min
Ordinary Hazard: EN OH1–OH4 5.0 mm/min (72 / 144 / 216 / 360 m²); NFPA OH1 6.1 / OH2 8.1
High / Extra Hazard: EN HHP1–3 7.5 / 10.0 / 12.5 mm/min (260 m²); NFPA EH1 12.2 / EH2 16.3

COVERAGE AREAS:
Light: EN 21 / NFPA 18.6–20.9 m² per sprinkler
Ordinary: EN 12 / NFPA 12.1 m² per sprinkler
High / Extra: EN 9 / NFPA 9.3 m² per sprinkler

Key Points:
  • Dual mode: Fire Cabinet or Sprinkler system
  • Multi-standard compliance (NFPA, EN, TS)
  • Automatic sprinkler count calculation
  • Pipe sizing with hydraulic analysis
  • Pump selection with safety margins
  • Tank volume per standard requirements
  • Standard comparison table
  • Compliance status indicator
  • Fire protection design report
  • Material list generation
Calculation Steps:
  1. Enter all required parameters
  2. Click "Update Calculation"
  3. Review results and analysis
Formula Variables:
Q Flow Rate (L/min)
P Pressure (bar)
K K-Factor (L/min·bar^0.5)
D Density (mm/min)
A Coverage Area (m²)
n Sprinkler Count (-)
Dpipe Pipe Diameter (mm)
V Velocity (m/s)
ΔP Pressure Loss (bar)
Vtank Tank Volume (m³)