HVAC Electrical Calculators

Free Ohm's law calculator: enter any two of voltage, current, resistance and power to solve the other two.

Calculate single-phase real power (W) and apparent power (VA) from voltage, current and power factor.

Calculate three-phase kW and kVA from line-to-line voltage, line current and power factor using √3.

Calculate three-phase line current from kW, voltage and power factor.

Calculate voltage drop for single or three-phase circuits by conductor size, material, current and length.

Calculate conductor resistance for copper or aluminum wire by AWG size and length.

Estimate motor full-load current from horsepower, voltage, efficiency and power factor for single or three-phase motors.

Calculate motor efficiency from mechanical output horsepower and electrical input kW.

Calculate 24 V control transformer load in VA and the next common transformer size.

Calculate a run capacitor's actual µF from measured current and voltage (µF = 2652 × A ÷ V at 60 Hz).

Calculate capacitive reactance Xc from frequency and capacitance.

Calculate total resistance of resistors in series and in parallel.

Calculate power factor and phase angle from real power, voltage and current.

Conductor Ampacity & Breaker Reference — coming soon to Welcome to HVAC once verified reference data is in place.