Power and energy

kW, kVA, kvar and power factor calculator

Resolve kW, kVA, kvar, power factor and phase angle for a sinusoidal load from two known values, with the reactive direction and the difference between total and displacement power factor shown.

Calculate

Known quantity pair
kW
kVA
kvar

Worked example

Apparent power

125 kVA

Active power
100 kW
Reactive power (inductive, lagging)
75 kvar
Power factor
0.8
Phase angle

Sinusoidal or fundamental-frequency triangle. Where the entered power factor includes waveform distortion, the angle is not the displacement angle.

Underlined figures are rounded. Select one to copy its full value.

Method and assumptions

Formula

S² = P² + Q²; PF = P ÷ S; |φ| = cos⁻¹(PF)

The Pythagorean triangle applies to sinusoidal or fundamental-frequency quantities. On distorted waveforms, total non-active power is not necessarily displacement kvar.

Limits of this result

  • Inputs and results are magnitudes; the selected leading/lagging direction supplies the sign of reactive power.
  • Do not infer displacement angle or compensation requirements from total PF where harmonics are material.
  • Capacitor sizing, switching and resonance checks require a separate engineering study.

Technical sources

  1. Calculation of electrical powers in Schneider Electric PMDsSchneider Electric · 7EN52-0464-00, 2022-03-18
  2. Power Factor: What it is and how to calculate itFluke · accessed 2026-09-14

Put the value to work

Read the related engineering guidance, or carry this task into System Builder to identify the signal path and EpiSensor products.

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