Fire alarm calculators.
Start with voltage drop, battery demand, detector layouts, or strobe candela. Work through a planning estimate before taking the next step.
Voltage drop
Estimate end-of-run voltage for a two-wire DC circuit.
Open tool02Battery sizing
Calculate standby and alarm demand in amp-hours.
Open tool03Detector layout
Explore a rectangular grid using your selected spacing.
Open tool04Notification planning
Compare room layouts, candela settings, and mounting heights.
Open toolChoose the calculation for the task
NAC voltage drop
The fire alarm voltage drop calculator estimates loss in a two-wire DC run and compares end voltage with the device minimum you enter. Its lumped-load model differs from a segmented, device-by-device calculation.
Standby and alarm battery demand
The fire alarm battery calculator combines total standby and alarm currents with the durations you specify, then applies a capacity multiplier. Use the result as an estimate before selecting manufacturer-supported equipment.
Detection and visible notification layouts
Use the smoke detector spacing calculator for a preliminary rectangular grid. Use the strobe candela and spacing calculator to compare room mounting arrangements, output settings, and a separate straight-corridor method.
Keep the assumptions with the job
Record the model, settings, circuit arrangement, reference edition, and input values behind each estimate. For project notes, app calculations, reports, and PDF markups, explore Fire Alarm Field Pro on iPhone and iPad.
Download on the App Store