Electrical Calculators
Fast, free calculators for electricians and engineers. Fast, accurate, and free — voltage drop, wire size, Ohm's law, three-phase power and more.
Electrical Calculators
Single-purpose tools for electricians, electrical engineers and makers. Metric and imperial, with region-tagged standards where they differ.
Voltage Drop Calculator
Voltage drop over a run by length, current and conductor (AWG/mm2, 1ph/3ph/DC)
Open calculatorWire Size Calculator
Smallest conductor that meets ampacity and the voltage-drop limit (AWG/mm2)
Open calculatorAWG Conversion Calculator
Convert AWG to mm2, circular mils, kcmil and diameter
Open calculatorOhm's Law Calculator
Solve voltage, current, resistance and power from any two
Open calculatorWatts Amps Volts Calculator
Convert between watts, volts and amps (DC, 1-phase, 3-phase)
Open calculatorThree-Phase Power Calculator
Three-phase power triangle: line current, kW, kVA, kVAR
Open calculatorkVA Calculator
Apparent power (kVA) from volts and amps, single or three phase
Open calculatorLED Resistor Calculator
Series resistor for an LED: ohms, power and nearest standard value
Open calculatorConduit Fill Calculator
NEC conduit fill percentage by conductor size and count
Open calculatorTransformer Sizing Calculator
Required transformer kVA and full-load amps from the load
Open calculatorBreaker / Fuse Sizing Calculator
Next standard breaker or fuse size for a load (NEC 240.6)
Open calculatorMotor FLA Calculator
Motor full-load amps from horsepower, voltage and phase
Open calculatorPower Factor Correction Calculator
Capacitor kVAR to correct power factor to a target
Open calculatorBattery Runtime Calculator
Runtime from battery capacity, voltage and load
Open calculatorSolar PV Sizing Calculator
Solar array size and panel count from daily energy use
Open calculatorEnergy Cost Calculator (kWh)
Energy use and running cost from power, hours and rate
Open calculatorResistor Colour Code Calculator
Resistor value from colour bands (4, 5 and 6 band)
Open calculatorFault Current Calculator
Available short-circuit current from transformer kVA and impedance
Open calculatorWatts to Amps Calculator
Current from power and voltage, DC, single and three-phase
Open calculatorAmps to Watts Calculator
Real power from current, voltage and power factor
Open calculatorkW to Amps Calculator
Line current from kilowatts for generators, motors and heaters
Open calculatorAmps to kW Calculator
Kilowatts from a current reading, single or three-phase
Open calculatorkVA to Amps Calculator
Transformer and generator full-load current from kVA
Open calculatorAmps to kVA Calculator
Apparent power from current and voltage for sizing supply equipment
Open calculatorkVA to kW Calculator
Real power and kVAR from apparent power and power factor
Open calculatorkW to kVA Calculator
Apparent power a generator or transformer must be rated for
Open calculatorHP to Amps Calculator
Motor running current from horsepower, efficiency and power factor
Open calculatorVolts to Amps Calculator
Current from voltage with either the load's watts or its ohms
Open calculatorAmpacity Chart
NEC 310.16 copper and aluminium ampacity at 60, 75 and 90 C, with AWG to mm2
Open calculator
Electrical Calculators
Fast, free calculators for electricians and engineers
Tools
- Voltage Drop Calculator
- Wire Size Calculator
- AWG Conversion Calculator
- Ohm's Law Calculator
- Watts Amps Volts Calculator
- Three-Phase Power Calculator
- kVA Calculator
- LED Resistor Calculator
- Conduit Fill Calculator
- Transformer Sizing Calculator
- Breaker / Fuse Sizing Calculator
- Motor FLA Calculator
- Power Factor Correction Calculator
- Battery Runtime Calculator
- Solar PV Sizing Calculator
- Energy Cost Calculator (kWh)
- Resistor Colour Code Calculator
- Fault Current Calculator
- All Tools
Guides
Resources
More Calculators
- Flow Rate Calculator Pump, pipe and flow rate tools
- Solar Sizing Calculator Solar, battery and off-grid sizing tools
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