Electrical calculations,
made simple.
Free, practical tools for fast everyday checks — from cable sizing and voltage drop to transformer currents and PV design. Clear results, transparent formulas and guidance when you need more detail.
I = 45000 / (√3 × 400 × 0.90)
Most used
Working engineering calculators, including our C/L field-testing tool.
Ohm's Law
Calculate voltage, current, resistance and electrical power with a step-by-step explanation.
Explore →Voltage Drop
Single-phase, three-phase and DC cable voltage drop with explained equations.
Explore →LV Cable Sizing
Get a preliminary minimum Cu/Al cable recommendation from current, length, PVC/XLPE and installation method; compare parallel runs and explore the math.
Explore →Three-Phase Power
Calculate current, kW, kVA, kvar and power factor with worked equations.
Explore →Engineering categories
Find the right tool for your next calculation.
Electrical Fundamentals
Core electrical quantities, AC power and essential conversions.
Cables & Distribution
Cable design, conductor checks and LV/MV distribution.
Power Systems
Transformers, short-circuit fault levels, UPS and power supply calculators for LV and MV electrical systems.
Power Quality
Power factor correction and reactive compensation components.
Motors & Industrial
Motor loading, starters and industrial drive systems.
Protection & Safety
Protection equipment, earthing and electrical safety.
Renewable Energy
Solar PV string design, battery compatibility and inverter calculators for grid-connected renewable energy systems.
Guides & reference
Illustrated lessons, standards, relay function numbers and formulas.