Three Phase Power Calculator: kW, kVA, kVAR and Current
Enter the line voltage (415 V in India), current and power factor to get kW, kVA and kVAR, or enter kW to get the current. Star and delta phase values are shown too.
- Nothing you type is stored
- Free
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Power
12.22kW
- Apparent power
- 14.38 kVA
- Reactive power
- 7.57 kVAR
- Phase voltage
- 239.6 V
- Phase current
- 20 A
Assumes a balanced load on all three phases.
Show working
- P = √3 × 415 × 20 × 0.85 = 12,220 W
- S = √3 × 415 × 20 = 14,376 VA
How to use
- Choose whether to find power or current.
- Enter line-to-line voltage, current (or kW) and power factor.
- Choose star or delta to see phase voltage and current.
Good to know
For a balanced three-phase load: P = √3 × V(line) × I(line) × PF; apparent power S = √3 × V × I; reactive power Q = √(S² − P²). Current for a known load: I = P ÷ (√3 × V × PF).
Star (Y): phase voltage = line voltage ÷ √3 (415 V → 240 V), phase current = line current. Delta (Δ): phase voltage = line voltage, phase current = line current ÷ √3.
For a motor, P here is the electrical input; shaft output is lower by the motor efficiency (often 85–95%). Unbalanced loads need each phase worked separately.
Questions
How many amps is a 10 kW three-phase load?
At 415 V and PF 0.85: 10,000 ÷ (1.732 × 415 × 0.85) = 16.4 A per line.
What is the formula for three-phase power?
P = √3 × V(L-L) × I × PF.
Why √3?
Because the three phase voltages are 120° apart, line voltage is √3 times phase voltage in a star system.
What is the phase voltage of 415 V supply?
415 ÷ 1.732 = 240 V (line to neutral).
What power factor should I use?
From the equipment plate; induction motors are often 0.8–0.9 at full load.