AC Power Calculator (Real, Reactive, Apparent)
Real power (W), reactive power (VAR) and apparent power (VA) for single- and three-phase AC circuits.
How to use the AC Power Calculator
- Enter or select: Voltage (RMS, line-to-line for 3-phase), Current (RMS), Power factor cos φ, System.
- The results (Apparent power S, Real power P, Reactive power Q, Phase angle φ) are calculated instantly as you type.
- Use “Copy link” to share the calculation with the same input values.
Formula
- S = V·I (×√3 for three-phase)
- P = S·cos φ, Q = S·sin φ