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MJ
Md Jony Islam
Last updated: Jun 3, 2026

3 phase power calculator

Compute 3-phase real power (kW), apparent (kVA), and reactive (kVAr) using √3·V·I and power factor. Supports line voltage/current and balanced loads.

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V
A
Pf
KW
KVA
KVAr
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3 phase power calculator

Compute 3-phase real power (kW), apparent (kVA), and reactive (kVAr) using √3·V·I and power factor. Supports line voltage/current and balanced loads.

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industrial load kW

For three phase balanced Load use P(kw) = √3 Vl(V) Il(A)pf / 1000 & S(kva) = √3 Vl Il / 1000. Reactive power is Q(kVAr) = P/tan – model(arccos(PF)).

Formula & Table Summary:

  • S (VA): √3 x VL x IL
  • P (W): √3 x VL x IL x PF
  • Q (VAr): √3 x VL x IL x sinφ    where φ = arccos(PF)
  • k-units: divide by 1000
  • Alt: Q (kVAr) = P (kW) x tan(arccos(PF))
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400V 3 phase kW; 415V 3 phase kW

The 3 Phase Power Calculator finds the real power (kW), apparent power (kVA), and reactive power (kVAr) of three-phased, balanced systems. To immediately obtain results, enter line-to-line voltage (V L ), line current (I L ),, and the power factor (PF). By definition, the apparent power is S = 1/2 3 VL IL. Real power gets power factor: P = 1/2 3 VL IL PF. The reactive power is obtained as a consequence of the phase angle 4: Q = 3-vector-root-of-3-times-V_L-times-I_L-times-sin4 (replacing the factor of sin4 by PF, the result is Q = P times tan (arccos (PF)). The results can be indicated in kW/ kVA/ kVAr after division by 1000. These formulae are used in motors, HVAC equipment, switchboards, and distribution feeders on a 3-phase network (e.g,. 208V, 400/415V, 480V). Use them to size conductors, breakers, transformers, or check nameplate ratings and energy demand. The calculator uses balanced loads, single-phase calculations may be used with single-phase or unbalanced systems, and adds the answers.

three-phase power calculator

V_L (V) I_L (A) PF S (kVA) P (kW) Q (kVAr)
400 50 0.85 34.64 29.45 18.56
415 80 0.90 57.49 51.74 24.92
480 100 0.80 83.14 66.51 49.89
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Frequently Asked Questions - 3 phase power calculator:

P(kW)=√3·V_L(V)·I_L(A)·PF/1000.
S(kVA)=√3·V_L·I_L/1000 for balanced loads.
Q(kVAr)=P·tan(arccos(PF)) or √3·V_L·I_L·sinφ/1000.
Use line-to-line voltage (e.g., 400/415/480 V) for the √3 formulas.
No, not directly. Frequency affects equipment behavior but not the algebra here.
Compute per phase and sum P, Q, and S. These closed forms assume balance.
Add capacitors/VFDs to reduce reactive power and current draw.
PF=P/S, with P in kW and S in kVA.
I_L= P(kW)·1000 /(√3·V_L·PF).
No. Efficiency links mechanical kW to electrical kW; PF links kW to kVA.
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