Power Factor Correction Calculator

Power Factor Correction

Results for guidance only. Verify against current standards and manufacturer data.
Not a substitute for engineering judgement or a licensed professional.

Methodology

Required capacitor kVAR is calculated as $Q_c = P\,(\tan\phi_1 - \tan\phi_2)$, where $\phi_1$ and $\phi_2$ are the power factor angles before and after correction ($\phi = \cos^{-1}(\mathrm{PF})$). This represents the reactive power the capacitor bank must supply to reduce the reactive power drawn from the supply, improving the overall power factor without changing real power consumption.

Assumptions & Limitations

• Assumes a linear, non-harmonic load — installations with VSDs or other harmonic sources require specialist assessment for detuning
• Suggested capacitor steps are indicative — actual available bank sizes vary by manufacturer
• Does not account for switching transients or inrush current on capacitor energisation