Tool library
Fire protection calculators
A focused library of free U.S. fire protection calculators organized by engineering workflow, input evidence, formula context, and NFPA standard.
30 calculators6 workflowsFree toolsPDF workpapers
Calculators
30
Interactive engineering tools
Workflows
6
Grouped by job task
Reference tables
8
Used for input setup
Page role
Use this page for a defined task before moving to the next project record.
- Audience
- Users who need a numeric fire protection screen before a worksheet, submittal, or field-review decision.
- Job
- Select the right calculator by task, confirm inputs, run the screen, and retain the result with units and warnings.
- Evidence
- Drawing values, device listings, field test records, selected reference rows, and project criteria.
- Output
- A calculator result with formula basis, warnings, PDF/print workpaper support, and downstream handoff.
- Next
- Open a quick-start task or workflow category, then use the result panel handoff for the next calculator.
Start here by job task
| Task | Open a calculator when | First calculator | Use a worksheet when |
|---|---|---|---|
| Sprinkler hydraulic check | Estimate friction loss or pressure drop for a known pipe segment. | Open tool | The result feeds density, demand, hose allowance, and supply comparison. |
| Fire alarm power check | Check battery capacity or voltage drop from known listed currents and route length. | Open tool | The circuit review needs battery, NAC, voltage-drop, and conductor records together. |
| Water supply comparison | Convert hydrant test data into available flow at a target residual pressure. | Open tool | A flow test must be retained with demand comparison and authority records. |
| Hazard basis setup | Screen hazard class, density, design area, or coverage before demand setup. | Open tool | The selected basis affects multiple sprinkler calculations or design assumptions. |
How this tool library is organized
- 1Start by job task: sprinkler hydraulics, fire alarm power, hazard setup, water supply, pump screening, or unit conversion.
- 2Confirm field values from drawings, device listings, flow test records, or reference tables before replacing defaults.
- 3Run the calculator, review warnings, then export or print the workpaper before moving the result into a downstream tool.
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.
| Worksheet | Engineering task | Workflow coverage | Deliverable | Open |
|---|---|---|---|---|
NFPA 13 Hydraulic Design Worksheet NFPA 13 | NFPA 13 hydraulic calculation, sprinkler hydraulic worksheet, sprinkler system demand calculator | Establish design criteria, Check sprinkler discharge, Check pipe hydraulics, Assemble system demand | Design criteria worksheet | Open |
Fire Alarm Battery and NAC Worksheet NFPA 72 | fire alarm battery calculator NFPA 72, NAC voltage drop calculator, fire alarm voltage drop worksheet | Build load schedule, Size standby battery, Check NAC load and voltage | Battery capacity worksheet | Open |
Hydrant Flow and Water Supply Worksheet NFPA 25 | hydrant flow test calculator, available water supply calculator, NFPA 25 flow test calculation | Record hydrant test, Calculate available water, Prepare demand comparison | Hydrant flow test calculation | Open |
Fire Pump Selection Worksheet Engineering | fire pump sizing calculator, fire pump horsepower calculator, NPSH fire pump calculator | Import demand, Screen pump output, Review suction condition | Pump flow and discharge pressure screen | Open |
Hazard Classification and Density Setup Worksheet NFPA 13 | NFPA 13 hazard classification, sprinkler density area curve, occupancy hazard classification worksheet | Classify occupancy, Select density and area, Prepare sprinkler coverage | Occupancy and hazard basis | Open |
Engineering workflows
Each workflow lists the inputs, outputs, formulas, references, and tools needed for a specific fire protection check.
| Workflow | When to use it | Inputs to collect | Outputs reviewed | Open |
|---|---|---|---|---|
NFPA 13 Sprinkler Tools NFPA 13 / 10 tools | Set occupancy hazard, density, design area, and sprinkler spacing. | Flow rate, Internal pipe diameter, C value, Density | Friction loss, Velocity, Sprinkler demand, System demand | Open |
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 resistance | Required AH, End-of-line voltage, NAC spare capacity, Adjusted spacing | Open |
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 area | Likely hazard class, Design criteria, Coverage area, Minimum flow | Open |
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 pressure | Hydrant flow, Available flow, Supply curve point, Residual pressure check | Open |
Fire Pump Tools Engineering / 3 tools | Start with sprinkler demand, hose allowance, elevation, and required pressure. | Pump flow, Total head, System demand, Elevation | Rated flow, Discharge pressure, Horsepower, NPSH available | Open |
Unit Conversion Tools Conversion / 4 tools | Normalize field values into the units required by the calculator. | Pressure, Flow, Length, Area | Converted value, Internal diameter, Reference-ready value | Open |
NFPA 13 Sprinkler Tools
10 tools for NFPA 13 screening and setup.
| Tool | Workflow role | Input basis | Primary outputs | Open |
|---|---|---|---|---|
Hazen-Williams NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Flow rate, Nominal pipe size, Pipe schedule | Pipe material, Hazen-Williams C value, Nominal pipe size | Open |
K-Factor NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Solve for, Listed K-factor, Pressure | Selected K-factor, K-factor use, Calculated value | Open |
Pipe Sizing NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Flow rate, Nominal pipe size, Pipe schedule | Nominal pipe size, Pipe schedule, Internal diameter | Open |
Sprinkler Density and Area NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Design density, Design area | Sprinkler demand | Open |
Sprinkler System Demand NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Design density, Remote area, Hose allowance | Sprinkler demand, Total demand, Elevation pressure | Open |
Pipe Velocity NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Flow rate, Nominal pipe size, Pipe schedule | Nominal pipe size, Pipe schedule, Internal diameter | Open |
Velocity Pressure NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Flow rate, Nominal pipe size, Pipe schedule | Nominal pipe size, Pipe schedule, Internal diameter | Open |
Remote Area NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Design density, Remote area, Sprinkler coverage area | Remote area, Coverage per sprinkler, Estimated sprinklers | Open |
Equivalent Length NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Straight pipe length, Nominal pipe size, Fitting type | Straight pipe length, Nominal pipe size, Fitting type | Open |
Fire Pump Sizing NFPA 13 | Screen sprinkler hydraulic assumptions before detailed hydraulic modeling. | Sprinkler demand, Hose allowance, Required system pressure | Sprinkler demand, Hose allowance, Rated flow screen | Open |
NFPA 72 Fire Alarm Tools
6 tools for NFPA 72 screening and setup.
| Tool | Workflow role | Input basis | Primary outputs | Open |
|---|---|---|---|---|
Fire Alarm Battery Capacity NFPA 72 | Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review. | Standby current, Standby duration, Alarm current | Required capacity, Final capacity, Suggested battery | Open |
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 length | Wire size, Conductor resistance, Round-trip length | Open |
Detector Spacing NFPA 72 | Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review. | Listed spacing, Ceiling condition factor, Environment factor | Listed spacing, Adjusted spacing, Coverage area screen | Open |
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 rating | Total circuit load, Spare capacity, Load percentage | Open |
Strobe Candela Coverage NFPA 72 | Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review. | Room length, Room width, Listed candela | Room area, Room diagonal, Representative max room size | Open |
Wire Resistance NFPA 72 | Check fire alarm circuit, battery, spacing, or notification appliance assumptions before submittal review. | Wire size, Circuit current, One-way length | Wire size, Conductor resistance, Round-trip length | Open |
Hazard Classification Tools
3 tools for NFPA 13 screening and setup.
| Tool | Workflow role | Input basis | Primary outputs | Open |
|---|---|---|---|---|
Occupancy Hazard Classifier NFPA 13 | Screen preliminary hazard class, density, area, or coverage assumptions before hydraulic calculations. | Occupancy use | Occupancy use, Selected hazard class, Classification rationale | Open |
Design Density NFPA 13 | Screen preliminary hazard class, density, area, or coverage assumptions before hydraulic calculations. | Hazard class | Selected hazard class, Design density, Design area | Open |
Sprinkler Coverage Area NFPA 13 | Screen preliminary hazard class, density, area, or coverage assumptions before hydraulic calculations. | Sprinkler spacing, Branch line spacing, Design density | Coverage area, Minimum flow | Open |
Water Supply Tools
4 tools for NFPA 25 screening and setup.
| Tool | Workflow role | Input basis | Primary outputs | Open |
|---|---|---|---|---|
Hydrant Flow Test NFPA 25 | Convert hydrant or flow test observations into water supply screening values. | Discharge coefficient, Outlet diameter, Pitot pressure | Hydrant flow | Open |
Pitot Flow NFPA 25 | Convert hydrant or flow test observations into water supply screening values. | Discharge coefficient, Outlet diameter, Pitot pressure | Hydrant flow | Open |
Available Water Supply NFPA 25 | Convert hydrant or flow test observations into water supply screening values. | Measured test flow, Static pressure, Residual pressure | Available flow | Open |
Water Supply Curve Plotter NFPA 25 | Convert hydrant or flow test observations into water supply screening values. | Measured test flow, Static pressure, Residual pressure | Available flow, Static pressure, Residual pressure | Open |
Fire Pump Tools
3 tools for Engineering screening and setup.
| Tool | Workflow role | Input basis | Primary outputs | Open |
|---|---|---|---|---|
Fire Pump Sizing Engineering | Screen pump flow, pressure, horsepower, or suction conditions before manufacturer curve review. | Sprinkler demand, Hose allowance, Required system pressure | Sprinkler demand, Hose allowance, Rated flow screen | Open |
Fire Pump Horsepower Engineering | Screen pump flow, pressure, horsepower, or suction conditions before manufacturer curve review. | Pump flow, Total head, Specific gravity | Pump horsepower, Next standard motor size, Pump efficiency | Open |
NPSH Engineering | Screen pump flow, pressure, horsepower, or suction conditions before manufacturer curve review. | Suction head, Atmospheric head, Suction friction loss | NPSH available, Required NPSH, NPSH margin | Open |
Unit Conversion Tools
4 tools for Conversion screening and setup.
| Tool | Workflow role | Input basis | Primary outputs | Open |
|---|---|---|---|---|
Pressure Unit Conversion | Normalize units before using another fire protection calculator. | Pressure value, From unit, To unit | Converted value, From unit, To unit | Open |
Flow Rate Conversion | Normalize units before using another fire protection calculator. | Flow value, From unit, To unit | Converted value, From unit, To unit | Open |
Pipe Dimension Reference Conversion | Normalize units before using another fire protection calculator. | Nominal pipe size, Pipe schedule | Nominal pipe size, Pipe schedule, Selected internal diameter | Open |
Length and Area Unit Conversion | Normalize units before using another fire protection calculator. | Length or area value, From unit, To unit | Converted value, From unit, To unit | Open |