Three-Phase Power Calculator

Calculate kW, kVA, and kVAR for a balanced 3-phase load from voltage, current, and power factor.

How to Use

  1. Select how your voltage is specified: Line-to-Line (VLL) or Line-to-Neutral (VLN).
  2. Enter voltage and line current, then set power factor (PF).
  3. (Optional) Add efficiency to estimate output power to a load/motor.
  4. Open Show Work for formulas and steps.
System Readout
Balanced 3-phase model (standard engineering formulas).
kW
—
kVA
—
kVAR
—
PF
—
Status: —
3φ Source 3φ L1 L2 L3 Balanced 3φ Load V = — I = — PF = — kW = — Uses standard balanced 3φ formulas (P, S, Q) with √3 scaling.
Inputs & Settings
Enter values to calculate power for a balanced 3-phase system.
If you enter VLN, the calculator converts to VLL = √3 × VLN.
Optional (display/reference). Common: 50 Hz, 60 Hz.
Enter VLL or VLN based on “Voltage Spec”.
This is line current for the balanced 3-phase load.
PF range: 0 to 1. Used for kW and phase angle.
If set, estimates output kW = input kW × (eff%).
Show Work (step-by-step)
—
Work is shown using base units (V, A, W/VA/VAR) and √3 where applicable.

Reference (Balanced 3-Phase)

For balanced three-phase systems using line-to-line voltage (VLL) and line current (I):

  • Apparent power: S = √3 × VLL × I
  • Real power: P = √3 × VLL × I × PF
  • Reactive power: Q = √3 × VLL × I × sin(φ)
  • Angle from PF: φ = arccos(PF)
  • Convert voltage spec: VLL = √3 × VLN
This tool assumes a balanced load for the primary calculation model.

FAQ

Is this for single-phase or three-phase?

This tool is for balanced three-phase systems (common for motors, VFDs, and industrial loads).

What if I only know line-to-neutral voltage?

Select Line-to-Neutral (VLN). The calculator converts to VLL using √3.

What does kVA vs kW mean?

kVA is total apparent power; kW is usable real power after power factor is applied.

Does leading vs lagging PF change kW?

kW magnitude is the same for a given PF value, but leading/lagging indicates the direction of reactive power (capacitive vs inductive).

Tool Info

Last updated:

Updates may include additional solve modes, unit support, and edge-case handling.