Method: Required reactive compensation is calculated from: Q_c = P × [tan(φ₁) − tan(φ₂)] where: φ₁ = cos⁻¹(PF₁) φ₂ = cos⁻¹(PF₂) P is real power, PF₁ is the existing power factor and PF₂ is the target power factor. Existing reactive power: Q₁ = P × tan(φ₁) Corrected reactive power: Q₂ = P × tan(φ₂) Apparent power before correction: S₁ = P ÷ PF₁ Apparent power after correction: S₂ = P ÷ PF₂ The calculated kVAr is the theoretical capacitive reactive power required at the stated operating load. Actual capacitor-bank selection normally uses available standard kVAr steps and should account for load variation, switching strategy, harmonics, utility requirements and equipment ratings. Avoid unnecessary overcorrection. Systems with variable loads may require automatically switched capacitor banks rather than a fixed bank.