Three-Phase Voltage Calculator

Three-phase power systems use three alternating currents to deliver electricity in industrial and commercial settings — this Three-Phase Voltage Calculator converts your electrical parameters into a full power breakdown. Enter your line-to-line voltage, current, and power factor, then select a connection type (Star or Delta) to get apparent power (kVA), along with active power, reactive power, phase voltage, and phase current. Also try the calculate Delta to Star (Wye) Conversion.

Results

Apparent Power

Active Power

Reactive Power

Phase Voltage

Phase Current

What is apparent power in a three phase circuit?

Apparent power is the total power in a three-phase circuit, measured in volt-amperes (VA) or kilovolt-amperes (kVA). It represents the combination of active power (which does useful work) and reactive power (which is stored and released by reactive components). See also our Three-Phase Current Calculator.

How do I calculate apparent power using line voltage and current?

For three-phase systems, apparent power (S) is calculated using the formula: S = √3 × VL × IL, where VL is the line-to-line voltage and IL is the line current. The √3 factor (approximately 1.732) accounts for the three-phase relationship.

What is the difference between active power and apparent power?

Active power (kW) is the actual power consumed to do useful work, while apparent power (kVA) is the total power supplied to the circuit. Active power equals apparent power multiplied by the power factor: P = S × cos(φ).

What is reactive power and why is it important?

Reactive power (kVAR) is the power that oscillates between the source and reactive components like inductors and capacitors. It doesn't do useful work but is necessary for maintaining voltage levels and magnetic fields in motors and transformers.

What is the difference between star and delta connections?

In star (Y) connection, phase voltage equals line voltage divided by √3, while phase current equals line current. In delta (Δ) connection, phase voltage equals line voltage, while phase current equals line current divided by √3.

How do I calculate three phase current?

Three-phase current depends on the known parameters. If you know apparent power and voltage: I = S/(√3 × V). If you know active power: I = P/(√3 × V × cos(φ)). The √3 factor accounts for the three-phase system.

Why is the power factor important in three-phase calculations?

Power factor (cos φ) indicates how efficiently electrical power is being used. A power factor of 1.0 means all power is being used for useful work, while lower values indicate reactive power is present, requiring higher current for the same active power.

How accurate are three-phase power calculations?

Three-phase power calculations are very accurate for balanced systems where all three phases have equal voltage magnitudes and are 120° apart. In unbalanced systems, individual phase calculations may be needed for precise results.