Electrical Tools &Calculators
Professional BS 7671 compliant calculators for UK electricians. Free, accurate, and built for real-world electrical installations.
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BS 7671 Tools
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Circuit Design
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Specialized
Free
All Tools
New Professional Calculators
Advanced BS 7671 compliance tools for testing and design
BS 7671 Professional Calculators
Advanced compliance tools for testing, design verification, and regulatory calculations
Earthing & Bonding Calculator
Calculate main earthing, protective bonding, and CPC sizes using BS 7671 regulations
Max Zs Calculator
Calculate maximum earth fault loop impedance for MCBs and fuses per BS 7671 Table 41.3
Ring Final Circuit Calculator
Calculate continuity test values and verify ring circuit design according to BS 7671 Appendix 15
Diversity & Maximum Demand Calculator
Calculate maximum demand with diversity factors for all premises types per BS 7671 Regulation 311.1
Prospective Fault Current Calculator
Calculate PSCC and PEFC to determine breaking capacity requirements per BS 7671 Regulation 612.11
Installation Cost Estimator
Estimate costs for electrical installation work across the UK with 2025 pricing
Circuit Design Calculators
Essential tools for designing and sizing electrical circuits
Cable Size Calculator
Calculate the correct cable size for UK electrical installations with BS 7671 compliance
Voltage Drop Calculator
Calculate voltage drop for single and three-phase circuits with BS 7671 compliance checks
Load Calculator
Calculate electrical loads and circuit breaker sizing with diversity factors
Circuit Breaker Selector
Select the correct MCB or RCBO for your circuit
Specialized Calculators
Purpose-built tools for specific electrical applications
EV Charger Calculator
Calculate electrical requirements for electric vehicle charging installation
Solar Panel Calculator
Size photovoltaic systems and calculate generation, costs, and payback
LED Savings Calculator
Calculate energy and cost savings from switching to LED lighting
Conduit Fill Calculator
Determine how many cables can fit in conduit according to BS 7671
Wire Length Calculator
Calculate total cable length and quantities for electrical projects
Reference Guides
Interactive guides and reference materials
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