Capacitor Bank Size Calculator
Use this capacitor bank sizing workflow for early power-factor correction screening when you need both kVAR and capacitance math.
- Current reactive power
- kVAR
- Target reactive power
- kVAR
- Required correction
- kVAR
- Capacitance per phase
- uF
- Connection divisor
- x
Calculation details
- Frequency used
- Hz
- Calculation basis
- Selection boundary
Recent results
Formulas
- Current kVAR = kW x tan(arccos(current power factor))
- Target kVAR = kW x tan(arccos(target power factor))
- Required correction kVAR = current kVAR - target kVAR
- Capacitance per phase = required kVAR x 1000 / (connection divisor x 2 x pi x frequency x voltage^2)
Use this calculator
Estimate required correction kVAR and capacitance per phase from kW, current power factor, target power factor, voltage, frequency, and capacitor connection.
Read the result
Review the calculated values with their displayed units and assumptions. The result is a planning aid for the stated inputs, not a final equipment or installation decision.
Check before final work
This capacitor bank size estimate is a screening calculation. It does not select capacitor equipment, harmonic filters, switching controls, fusing, utility approval, or code compliance.
FAQs
Does this choose a capacitor bank?
No. It estimates correction kVAR and capacitance only. Real equipment selection needs harmonics, resonance, switching, protection, utility, and manufacturer review.
Why does target power factor need to be higher?
This workflow estimates correction from the current condition toward a better target. A lower target would not be a correction requirement.
What does the connection divisor mean?
It is the arithmetic divisor used by this simple capacitance estimate. Confirm the actual capacitor connection and voltage basis with manufacturer data.