Toolnoza

Electrical & Lighting

Calculate voltage drop, cable cross-section, circuit values and illuminance.

Engineering Tools

Transformer kVA CalculatorConvert volts and amps to transformer kVA for single-phase or three-phase systems, or convert kVA back to current.Voltage Drop CalculatorEstimate resistive voltage drop and receiving voltage for copper or aluminum DC, single-phase or three-phase circuits.Cable Size CalculatorEstimate minimum metric cable cross-section for your voltage-drop limit, current, length and conductor temperature.Conduit Fill CalculatorCalculate conduit fill percentage for multiple cable groups and the required internal diameter for your chosen limit.Lighting Lux CalculatorEstimate average lux, foot-candles and luminaire count from room area, lumens and utilization and maintenance factors.Battery Runtime CalculatorEstimate how long a battery can power a load from usable capacity, depth of discharge and inverter efficiency.Solar Battery Size CalculatorEstimate the nominal battery capacity needed for daily energy use, backup days, usable depth of discharge and inverter losses.Generator Fuel Consumption CalculatorEstimate liters, fuel cost and runtime from the manufacturer’s fuel rate at your load.VFD Energy Savings CalculatorEstimate centrifugal fan or pump electricity savings using speed ratio, drive efficiency, operating hours and tariff.Motor Starting Current CalculatorEstimate balanced three-phase motor running current, starting current and starting apparent power with a supplied current multiplier.Electric Bill Calculator — kWh & CostEstimate an electric bill from kWh and your price per kWh, or convert appliance watts and operating time to energy and cost.Ohms to Kiloohms ConverterConvert electrical resistance from ohms (Ω) to kiloohms (kΩ), or back, with an exact decimal result.

Practical guides: Electrical & Lighting

How to Calculate VFD Energy Savings: Formula & ExampleEstimate centrifugal fan or pump electricity savings using speed ratio, drive efficiency, operating hours and tariff.How to Calculate Motor Starting Current: Formula & ExampleEstimate balanced three-phase motor running current, starting current and starting apparent power with a supplied current multiplier.Transformer kVA Calculation: Single-Phase & Three-Phase FormulaConvert volts and amps to transformer kVA for single-phase and three-phase circuits, or calculate amps from kVA. Includes formulas and examples.How to Calculate Voltage Drop: Formula and Worked ExampleLearn the voltage drop formula for copper and aluminum circuits, account for conductor temperature, and check a worked DC and three-phase example.Cable Size Calculation: Find the Cross-Section for Voltage DropCalculate minimum cable cross-section in mm² from current, length and voltage-drop limit, then understand why ampacity needs a separate check.