# Three-phase power calculator

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

## See Also

- Cable sizing calculator AS/NZS3008
- Maximum demand calculator AS/NZS3000
- Arc Flash Calculator IEEE 1584

## 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.