Power Factor Correction Capacitor Sizing Calculator
How big a capacitor bank, and what does it actually buy you? The kVA and current it frees, the demand charge it saves — and whether it would resonate with your drives and destroy itself.
Your load
Whichever figure your meter or bill actually gives you
Your average or billed demand, not the connected total
kW
Line to line
V
Advanced / Custom Input — the load
Decides where a detuned reactor lands.
Hz
To show how much capacity the correction frees up. 0 to skip.
kVA
Where you are, and where you want to be
From your bill or a meter reading
Filled in from your country’s typical threshold
Advanced / Custom Input — the target
One fixed bank, or several steps on an automatic controller.
nos
Drives and electronics on the same bus
This is the section that decides whether the bank survives. A plain capacitor bank on a harmonic-rich bus can resonate and fail within months.
Needed for the resonance check — the calculation nobody else does
MVA
Advanced / Custom Input — harmonics
Above 5% is a detuning trigger. 0 if you have not measured.
%
Above 15% is a detuning trigger. 0 if you have not measured.
%
0 for a plain bank. 7% is standard for 5th-harmonic environments, 14% for 3rd.
%
What it costs and what it saves
Per kVA per month, from your bill. 0 to skip.
/kVA/mo
Per month. 0 if you do not pay one.
/mo
Advanced / Custom Input — the business case
Detuned banks cost meaningfully more than plain ones.
/kVAR
On top of the per-kVAR cost.
Result
Put in your load and your present power factor, then press “Size the bank”.
Estimate only — verify with a licensed engineer and your local code authority before final design or installation. A real capacitor bank installation needs a harmonic study.