Power Factor Correction Capacitor Calculator
Calculate ideal fundamental-frequency reactive correction, per-capacitor capacitance and line-current change for entered lagging power factors.
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Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Find the reactive-power difference from the two power-factor angles and convert it to equal ideal capacitor values for the selected arrangement.
Qc=P[tan(acos(PFbefore))−tan(acos(PFafter))]; Qc=ωCV²,3ωCVline² or ωCVline²
Worked example
For 10 kW, changing lagging PF from 0.8 to 1 removes 7.5 kvar in the sinusoidal model. A delta bank divides that correction among three equal capacitors at line voltage.
Assumptions and input details
Target PF must be at least starting PF, both positive and at most unity. This corrects displacement reactive power in a sinusoidal model, not harmonic distortion. Capacitance is per capacitor/phase. Resonance, switching, discharge, protection, voltage ratings, regulations and installation design are not assessed. No real capacitor bank is selected.
References: Schneider Electric: active, reactive and apparent power-factor basis
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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