Electrical Engineering
Calculation Tools
Professional-grade tools for cable sizing, lighting design, transformer selection, and more. Built on IEC, IS & BS standards.
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Available Calculators
Cable Sizing
Size cables for any circuit — load current, voltage drop, derating for temperature, grouping & installation method.
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Lux Level Coming Soon
Interactive room layout with real-time lux heatmap. Place luminaires and visualise light distribution.
Transformer Sizing Coming Soon
Select transformer KVA rating based on connected load, power factor, demand factor and efficiency.
Voltage Drop Coming Soon
Calculate voltage drop across any cable run with full derating and reactive component.
Motor Sizing Coming Soon
Size cables and protective devices for motor circuits with starting current consideration.
Power Factor Correction Coming Soon
Calculate capacitor bank size required to correct power factor to target value.
Free electrical engineering calculators
Caltrical provides practical online calculation tools for electrical engineers, electricians, contractors, students, and panel designers. Start with the cable sizing calculator to check current capacity and voltage drop for single-phase and three-phase circuits.
Use load current, voltage, cable length, power factor, installation method, ambient temperature, and grouping to review a cable selection. Results are intended for preliminary design and must be verified against the project specification, manufacturer data, and applicable local regulations.
Open the cable sizing calculator