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Three-phase power calculator

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

See Also

3-phase power calculator 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. Its between 0 and 1.

How to calculate 3-phase power?

The 3-phase power formula for active power is:

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

Where,

  • \(V_{LL}\) is the 3-phase line voltage,
  • \(I\) is the current, and
  • \( \cos \phi \) is the power factor between 0 and 1.

The 3-phase power formula for apparent power is:

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

Where,

  • \(V_{LL}\) is the 3-phase line voltage, and
  • \(I\) is the current.

The 3-phase power formula for reactive power is:

\(Q_{kvar}=\dfrac{\sqrt{3} \cdot V_{LL} \cdot I \cdot \sin{\phi}}{ 1000 }\)

Where,

  • \( \sin{\phi} = \sqrt{ 1 -(\cos{\phi)}^2}\), and
  • \( \cos \phi \) is the power factor between 0 and 1.

Alternative 3-phase power formula for reactive power is:

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

Where,

  • \(S_{kVA}\) is the 3-phase apparent power, and
  • \(P_{kW}\) is the 3-phase active power.

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