Fire Alarm Tools & Calculators
Free interactive tools built for fire alarm technicians. All calculations run right in your browser — giving you instant results with no sign-up required.
Available Tools
Ohm's Law Calculator
Calculate voltage, current, resistance, and power. Enter any two values — the rest are solved instantly.
Battery Sizing Calculator
Calculate required battery AH capacity for fire alarm systems. NFPA 72 standby and alarm duration support.
Amp Draw Calculator
Add devices to calculate total standby and alarm current draw. Feed results into battery sizing.
Voltage Drop Calculator
Calculate voltage at each device on a NAC or speaker circuit. Pass/fail indicators per manufacturer specs.
In Development
Resistor Color Band Visualizer
Interactive visual resistor with color band selection and EOL value highlights.
DIP Switch Calculator
Visual DIP switch bank with binary/decimal/hex conversion and panel presets.
Conduit Fill Calculator
Visual conduit cross-section with real-time fill percentage as wires are added.