A comprehensive suite of calculators designed to assist fire and security engineers with system design, compliance calculations, and equipment sizing. Select a calculator below to get started.
Battery Calculator
Calculate minimum battery capacity (Cmin) for fire alarm systems using BS 5839 standards with 24-hour standby and 30-minute alarm duration.
DIP Switch Calculator
Calculate binary DIP switch settings for addressable fire detector addressing with support for Apollo, Hochiki, and other major protocols.
Sounder Test Tool
Test tool to emulate many standard tones as specified in BS5839. Great for testing audio triggered door retainers!
Fire and Security Cable Calculator
Calculate voltage drop, resistance, capacitance, and inductance for security, fire alarm, data, and power cables. Includes practical application advice for different cable types.
Ohm's Law Calculator
Calculate voltage, current, resistance, and power relationships for electrical circuit design and troubleshooting.
Smoke Detector Calculator
Estimate the number of smoke detectors required based on floor area, ceiling height, and BS 5839-6 coverage requirements.
Fire Extinguisher Calculator
Determine the number and placement of fire extinguishers needed for Class A combustibles based on area and hazard level.
Fire Alarm Sounder Calculator
Estimate the number of sounders required for adequate coverage based on floor area, sounder output levels, barriers, acoustic absorption, ceiling height, and BS 5839-1 application-specific requirements.
⚠️ Disclaimer and Important Information
These calculators are provided as guidance tools only and are not guaranteed to be accurate, complete, or suitable for all applications.
Users must:
- Verify all calculations independently before implementation
- Consult current legislation, standards, and regulations (including BS 5839, BS 5306, and relevant building regulations)
- Engage qualified fire safety professionals for system design and installation
- Ensure compliance with all applicable local, national, and international standards
- Conduct proper risk assessments and site surveys
- Never rely solely on calculator outputs for critical safety systems
The author accepts no liability for any errors, omissions, or consequences arising from the use of these calculators. Professional judgment and expert consultation should always take precedence over automated calculations.
Fire and security systems are life-safety critical. Always prioritize safety and compliance over convenience.