NFPA in USA

Tool library

Fire protection calculators

A complete tool-first library organized by engineering workflow, input data, formula context, and NFPA standard.

30 calculators6 workflowsLight-only engineering UINo account required

Calculators

30

Interactive engineering tools

Workflows

6

Grouped by job task

Reference tables

8

Used for input setup

How this tool library is organized

  1. 1Start with the engineering workflow that matches the task: sprinkler, fire alarm, hazard, water supply, pump, or conversion.
  2. 2Use the visible input checklist and reference tables to select field values before calculating.
  3. 3Open the calculator page to review formula basis, result flags, related tools, and professional-use limitations.

Reference data before calculation

Start with a worksheet when the task is a complete job

Worksheets connect multiple calculators, reference tables, QA gates, and saved records for hydraulic, alarm, water supply, pump, and hazard setup workflows.

WorksheetEngineering taskWorkflow coverageDeliverableOpen

NFPA 13 Hydraulic Design Worksheet

NFPA 13

NFPA 13 hydraulic calculation, sprinkler hydraulic worksheet, sprinkler system demand calculatorEstablish design criteria, Check sprinkler discharge, Check pipe hydraulics, Assemble system demandDesign criteria worksheetOpen

Fire Alarm Battery and NAC Worksheet

NFPA 72

fire alarm battery calculator NFPA 72, NAC voltage drop calculator, fire alarm voltage drop worksheetBuild load schedule, Size standby battery, Check NAC load and voltageBattery capacity worksheetOpen

Hydrant Flow and Water Supply Worksheet

NFPA 25

hydrant flow test calculator, available water supply calculator, NFPA 25 flow test calculationRecord hydrant test, Calculate available water, Prepare demand comparisonHydrant flow test calculationOpen

Fire Pump Selection Worksheet

Engineering

fire pump sizing calculator, fire pump horsepower calculator, NPSH fire pump calculatorImport demand, Screen pump output, Review suction conditionPump flow and discharge pressure screenOpen

Hazard Classification and Density Setup Worksheet

NFPA 13

NFPA 13 hazard classification, sprinkler density area curve, occupancy hazard classification worksheetClassify occupancy, Select density and area, Prepare sprinkler coverageOccupancy and hazard basisOpen

Engineering workflows

Each workflow lists the inputs, outputs, formulas, references, and tools needed for a specific fire protection check.

WorkflowWhen to use itInputs to collectOutputs reviewedOpen

NFPA 13 Sprinkler Tools

NFPA 13 / 10 tools

Set occupancy hazard, density, design area, and sprinkler spacing.Flow rate, Internal pipe diameter, C value, DensityFriction loss, Velocity, Sprinkler demand, System demandOpen

NFPA 72 Fire Alarm Tools

NFPA 72 / 6 tools

Collect standby current, alarm current, circuit length, conductor resistance, and device load.Standby current, Alarm current, Circuit length, AWG resistanceRequired AH, End-of-line voltage, NAC spare capacity, Adjusted spacingOpen

Hazard Classification Tools

NFPA 13 / 3 tools

Screen occupancy use and fuel loading against broad hazard class examples.Occupancy use, Hazard class, Design density, Design areaLikely hazard class, Design criteria, Coverage area, Minimum flowOpen

Water Supply Tools

NFPA 25 / 4 tools

Enter hydrant test data, pitot pressure, outlet diameter, static pressure, and residual pressure.Static pressure, Residual pressure, Test flow, Pitot pressureHydrant flow, Available flow, Supply curve point, Residual pressure checkOpen

Fire Pump Tools

Engineering / 3 tools

Start with sprinkler demand, hose allowance, elevation, and required pressure.Pump flow, Total head, System demand, ElevationRated flow, Discharge pressure, Horsepower, NPSH availableOpen

Unit Conversion Tools

Conversion / 4 tools

Normalize field values into the units required by the calculator.Pressure, Flow, Length, AreaConverted value, Internal diameter, Reference-ready valueOpen

NFPA 13 Sprinkler Tools

10 tools for NFPA 13 screening and setup.

ToolWorkflow roleInput basisPrimary outputsOpen

Hazen-Williams

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Flow rate, Nominal pipe size, Pipe schedulePipe material, Hazen-Williams C value, Nominal pipe sizeOpen

K-Factor

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Solve for, Listed K-factor, PressureSelected K-factor, K-factor use, Calculated valueOpen

Pipe Sizing

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Flow rate, Nominal pipe size, Pipe scheduleNominal pipe size, Pipe schedule, Internal diameterOpen

Sprinkler Density and Area

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Design density, Design areaSprinkler demandOpen

Sprinkler System Demand

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Design density, Remote area, Hose allowanceSprinkler demand, Total demand, Elevation pressureOpen

Pipe Velocity

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Flow rate, Nominal pipe size, Pipe scheduleNominal pipe size, Pipe schedule, Internal diameterOpen

Velocity Pressure

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Flow rate, Nominal pipe size, Pipe scheduleNominal pipe size, Pipe schedule, Internal diameterOpen

Remote Area

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Design density, Remote area, Sprinkler coverage areaRemote area, Coverage per sprinkler, Estimated sprinklersOpen

Equivalent Length

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Straight pipe length, Nominal pipe size, Fitting typeStraight pipe length, Nominal pipe size, Fitting typeOpen

Fire Pump Sizing

NFPA 13

Screen sprinkler hydraulic assumptions before detailed hydraulic modeling.Sprinkler demand, Hose allowance, Required system pressureSprinkler demand, Hose allowance, Rated flow screenOpen

NFPA 72 Fire Alarm Tools

6 tools for NFPA 72 screening and setup.

ToolWorkflow roleInput basisPrimary outputsOpen

Fire Alarm Battery Capacity

NFPA 72

Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review.Standby current, Standby duration, Alarm currentRequired capacity, Final capacity, Suggested batteryOpen

Fire Alarm NAC Voltage Drop

NFPA 72

Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review.Wire size, Circuit current, One-way circuit lengthWire size, Conductor resistance, Round-trip lengthOpen

Detector Spacing

NFPA 72

Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review.Listed spacing, Ceiling condition factor, Environment factorListed spacing, Adjusted spacing, Coverage area screenOpen

NAC Circuit Load

NFPA 72

Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review.Appliance count, Current per appliance, Power supply ratingTotal circuit load, Spare capacity, Load percentageOpen

Strobe Candela Coverage

NFPA 72

Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review.Room length, Room width, Listed candelaRoom area, Room diagonal, Representative max room sizeOpen

Wire Resistance

NFPA 72

Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review.Wire size, Circuit current, One-way lengthWire size, Conductor resistance, Round-trip lengthOpen

Hazard Classification Tools

3 tools for NFPA 13 screening and setup.

ToolWorkflow roleInput basisPrimary outputsOpen

Occupancy Hazard Classifier

NFPA 13

Screen preliminary hazard class, density, area, or coverage assumptions before hydraulic calculations.Occupancy useOccupancy use, Selected hazard class, Classification rationaleOpen

Design Density

NFPA 13

Screen preliminary hazard class, density, area, or coverage assumptions before hydraulic calculations.Hazard classSelected hazard class, Design density, Design areaOpen

Sprinkler Coverage Area

NFPA 13

Screen preliminary hazard class, density, area, or coverage assumptions before hydraulic calculations.Sprinkler spacing, Branch line spacing, Design densityCoverage area, Minimum flowOpen

Water Supply Tools

4 tools for NFPA 25 screening and setup.

ToolWorkflow roleInput basisPrimary outputsOpen

Hydrant Flow Test

NFPA 25

Convert hydrant or flow test observations into water supply screening values.Discharge coefficient, Outlet diameter, Pitot pressureHydrant flowOpen

Pitot Flow

NFPA 25

Convert hydrant or flow test observations into water supply screening values.Discharge coefficient, Outlet diameter, Pitot pressureHydrant flowOpen

Available Water Supply

NFPA 25

Convert hydrant or flow test observations into water supply screening values.Measured test flow, Static pressure, Residual pressureAvailable flowOpen

Water Supply Curve Plotter

NFPA 25

Convert hydrant or flow test observations into water supply screening values.Measured test flow, Static pressure, Residual pressureAvailable flow, Static pressure, Residual pressureOpen

Fire Pump Tools

3 tools for Engineering screening and setup.

ToolWorkflow roleInput basisPrimary outputsOpen

Fire Pump Sizing

Engineering

Screen pump flow, pressure, horsepower, or suction conditions before manufacturer curve review.Sprinkler demand, Hose allowance, Required system pressureSprinkler demand, Hose allowance, Rated flow screenOpen

Fire Pump Horsepower

Engineering

Screen pump flow, pressure, horsepower, or suction conditions before manufacturer curve review.Pump flow, Total head, Specific gravityPump horsepower, Next standard motor size, Pump efficiencyOpen

NPSH

Engineering

Screen pump flow, pressure, horsepower, or suction conditions before manufacturer curve review.Suction head, Atmospheric head, Suction friction lossNPSH available, Required NPSH, NPSH marginOpen

Unit Conversion Tools

4 tools for Conversion screening and setup.

ToolWorkflow roleInput basisPrimary outputsOpen

Pressure Unit

Conversion

Normalize units before using another fire protection calculator.Pressure value, From unit, To unitConverted value, From unit, To unitOpen

Flow Rate

Conversion

Normalize units before using another fire protection calculator.Flow value, From unit, To unitConverted value, From unit, To unitOpen

Pipe Dimension Reference

Conversion

Normalize units before using another fire protection calculator.Nominal pipe size, Pipe scheduleNominal pipe size, Pipe schedule, Selected internal diameterOpen

Length and Area Unit

Conversion

Normalize units before using another fire protection calculator.Length or area value, From unit, To unitConverted value, From unit, To unitOpen