HVAC electrical calculators
Electrical arithmetic for HVAC equipment: Ohm’s law and AC power, motor current and load, voltage imbalance and meter readings. They do not size wires or breakers — the nameplate and the electrical code do.
Ohm’s Law and Electrical Power Calculator
Solve voltage, current, resistance and power from any two, and real power for single- and three-phase AC loads with power factor.
Answers: How do I calculate amps, volts, ohms or watts?
Motor Amps and Load Calculator
Estimate a motor’s input power and current from horsepower, efficiency and power factor, or its actual load from measured volts, amps and power factor (DOE method).
Answers: How many amps does my motor draw, and how loaded is it?
Voltage Imbalance Calculator (Three-Phase)
Calculate percent voltage (or current) imbalance from three line readings — the maximum deviation from the average divided by the average.
Answers: Is the voltage imbalance on my three-phase motor too high?
Electric Meter Watts Calculator (Kh Method)
Measure how much power the house (or one appliance) is drawing by timing the meter’s disk or pulse light, using its Kh constant.
Answers: How many watts is my air conditioner using, measured at the meter?
Arithmetic, not code compliance
These tools do the electrical arithmetic technicians use every day — power from volts, amps and power factor; motor current and load; voltage unbalance; capacitor checks; and power measured at the meter. They do not size conductors, breakers or overload protection: those come from the equipment nameplate and the electrical code adopted where you work. Work on energised equipment only if you are qualified to do so.