Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Line (V) (V)

Required number input.

Line Current (A) (A)

Required number input.

Power Factor

Required number input.

Calculate positive reactive-power magnitude for a balanced three-phase motor from line voltage, line current, and power factor. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Reactive Power Var

The resulting reactive power var returned as a number.

• Compact electronics formulas omit some combination of tolerances, temperature drift, bandwidth, loading, parasitics, noise spectrum, nonlinearity, clipping, calibration, layout, and device-specific limits. Typical datasheet values are not guaranteed limits.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Motor Power Factor At Load

  Calculate balanced three-phase motor power factor as real input power divided by √3 times line voltage and line current; the result is a magnitude.

• Reactive Power VAR

  Calculate signed reactive power in volt-amperes reactive from RMS voltage, RMS current, and phase angle.

• Headphone Impedance

  Calculate headphone impedance magnitude at a test frequency from RMS terminal voltage and RMS current; phase is not determined.