Three-phase power calculator

The three-phase power calculator calculates the apparent, active and reactive power for three-phase AC systems.

Voltage (V)

Current (A)

Power factor

Apparent power10.39 kVA
Active power8.83 kW
Reactive power5.47 kvar


The three phase power calculator calculates the active and reactive power current from the following parameters:

  • Voltage (V): Enter the phase-to-phase (\(V_{LL}\)) voltage for a 3-phase AC supply in volts.
  • Current (I): Enter the the current in Amperes (A).
  • Power factor (cosΦ). Enter the power factor of the load.

There-phase power calculation:

The three-phase apparent power \( S_{kVA}\) is calculated as:

\(S_{kVA}=\dfrac{ \sqrt{3} \cdot V_{LL} \cdot I}{ 1000 }\)


The three-phase active power \(P_{kW}\) (real power) is calculated as:

\(P_{kW}=\dfrac{\sqrt{3} \cdot V_{LL} \cdot I \cdot \cos \phi } { 1000 }\)


The three-phase reactive power \(Q_{kvar}\) is calculated as:

\(Q_{kvar}=\dfrac{\sqrt{3} \cdot V_{LL} \cdot I \cdot \sin{\phi}}{ 1000 }\), where \(\sin{\phi} = \sqrt{ 1 -\cos{\phi}^2}\)


Alternatively, the three-phase reactive power \(Q_{kvar}\) can be calculated as:

\(Q_{kvar}=\sqrt{ S_{kVA}^2 – P_{kW}^2 }\)