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Power Calculator

Calculate real, apparent and reactive power

Input Parameters

About This Calculator

  • DC: P = V × I
  • 1φ AC: S = V × I, P = S × PF
  • 3φ AC: S = √3 × V × I, P = S × PF

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How this power calculator works

For DC: P = V × I. For AC systems, apparent power S includes the power factor.

Three-phase uses the √3 factor: S = √3 × V × I. Real power P = S × PF, reactive Q = √(S² - P²).

FAQ

Three-phase power formula?

S = √3 × V × I. P = S × PF.

Real vs apparent power?

Real (W) = useful work. Apparent (VA) = total. P = S × PF.

What is power factor?

P/S ratio, 0-1. Higher = more efficient.

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