Power Factor Correction Calculator

Calculate required capacitor bank size (kVAR) and capacitance (µF) to improve power factor and reduce reactive power penalties.

Enter values and calculate

Before vs After Correction

Parameter Before After Improvement

Power Triangle Comparison

Formulas Used

Required Capacitor kVAR

Qc = P × (tan φ₁ − tan φ₂)

Capacitance — Single Phase (µF)

C = (Qc × 10⁶) / (2πfV²)

Capacitance — Three Phase Delta (µF per phase)

C = (Qc × 10⁶) / (3 × 2πfV²)

Capacitance — Three Phase Star (µF per phase)

C = (Qc × 10⁶) / (3 × 2πf × (V/√3)²)

Apparent Power

S = P / PF

Line Current (Three Phase)

I = (S × 1000) / (√3 × V)

Line Current (Single Phase)

I = (S × 1000) / V

Learn More:

Power Factor Correction Using Capacitor Bank — Calculation & Methods
What is Power Factor?
What is Reactive Power and Why is it Needed?
Difference Between kW, kVA, and kVAR

Calculation Assumptions

• Sinusoidal supply assumed
• Balanced load (three-phase systems)
• Negligible capacitor ESR (equivalent series resistance)
• No harmonic amplification considered
• Capacitor connected at rated voltage
• Unity voltage — no voltage rise from capacitor switching
• Preliminary capacitor sizing only
• Standard capacitor banks: 5, 7.5, 10, 12.5, 15, 20, 25, 30, 40, 50, 60, 75, 100, 125, 150, 200 kVAR