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Power Factor Correction Calculator

Calculate the required capacitor size (kVAR) to improve your facility's power factor and reduce electricity costs.

Check utility bill or measure with power analyzer

Recommended: 0.95 (avoid over-correction)

Formulas Used

Required kVAR: Qc = kW × (tan(θ1) - tan(θ2))
Where: θ = arccos(PF), Qc = capacitor kVAR
Apparent Power: kVA = kW / PF
Reactive Power: kVAR = kW × tan(θ) = √(kVA² - kW²)
Capacitor Current: I = kVAR × 1000 / (√3 × V)

Benefits of Power Factor Correction

  • Reduces utility demand charges (kVA-based billing)
  • Decreases line losses (I²R losses) in your distribution system
  • Increases system capacity without upgrading transformers/cables
  • Improves voltage regulation and equipment performance
  • May be required by utility to avoid penalty charges
  • Typical ROI: 1-3 years for industrial/commercial facilities
  • Target PF: 0.95 is recommended (avoid leading PF from over-correction)
  • Use automatic capacitor banks for varying loads
  • Size capacitors for 135% of rated voltage if harmonics present
  • Consider harmonic filters if significant non-linear loads exist