Quick answer: Required capacitor kVAR = P × (tanφ₁ − tanφ₂), where P is the real power (kW), φ₁ is the existing power-factor angle and φ₂ the target. Correcting PF cuts current, losses and demand charges.
The formula
kVAR = P × (tan(acos PF₁) − tan(acos PF₂))
P = real power (kW)
PF₁ = existing power factor, PF₂ = target power factorWorked example
Load 100 kW at PF 0.75, target 0.95: tan(acos 0.75)=0.882, tan(acos 0.95)=0.329. kVAR = 100 × (0.882−0.329) = 55.3 kVAR. Select the next standard capacitor bank (e.g. 60 kVAR), ideally in switched steps.
kVAR to reach any target power factor in seconds. Free tool.
Open the Power Factor Correction Calculator →Frequently Asked Questions
How do you calculate capacitor kVAR for power factor correction?
Multiply the real power in kW by the difference between the tangent of the existing power-factor angle and the tangent of the target angle: kVAR = P times (tan-phi1 minus tan-phi2).
Why improve power factor?
A higher power factor reduces current for the same real power, lowering cable losses, freeing transformer capacity and avoiding utility low-power-factor penalties.