Power Factor Calculator Widget
Add a power factor calculator to your website. Facility managers enter the load in kW with its power factor (or its kVA) and see the apparent and reactive power, and the capacitor bank size needed to raise the power factor to a target such as 0.95.
Live preview
Exactly what your visitors will seeUnder the widget on your page: Powered by A2Z Tools
Embed code
<iframe src="https://a2z.tools/embed/w/power-factor-calculator" title="Power Factor Calculator by A2Z Tools" width="100%" height="780" style="border:0;width:100%" loading="lazy" allow="clipboard-write"></iframe>
A plain iframe. Works everywhere, including site builders that strip scripts. Adjust height if your content needs more room.
<div data-a2z-widget="power-factor-calculator" data-height="780"></div> <script async src="https://a2z.tools/embed.js"></script>
Adds a small script (what it does) that sizes the widget to fit its content, loads it lazily and keeps it isolated from your page's CSS.
Works with
How it works
The widget uses the power-triangle functions shared by the A2Z electrical tools, following the sinusoidal power definitions of IEEE Std 1459. kVA is kW divided by the power factor, kVAR is the third side of the triangle, and the phase angle is acos(PF). The capacitor bank needed to move from the present angle to the target one is kW x (tan phi1 - tan phi2) - the same figure the printed multiplier tables in capacitor catalogues give (0.553 per kW from 0.75 to 0.95). It also shows how much the kVA, and so the current, falls after correction, and it says so when the load is already at or above the target.
Calculation method
- kVA = kW / PF; or PF = kW / kVA when kVA is known
- kVAR = sqrt(kVA^2 - kW^2); phase angle phi = acos(PF) in degrees
- Capacitor kVAR = kW x (tan(acos PF1) - tan(acos PF2)), shown to 2 decimals
- kVA after correction = kW / PF2; current falls in the ratio kVA2 / kVA1
Worked examples
Correcting a 100 kW load from 0.75 to 0.95
Inputs: 100 kW, PF 0.75, target 0.95
Result: 133.33 kVA, 88.19 kVAR, 41.41 degrees; capacitor bank 55.32 kVAR; kVA after correction 105.26
tan(41.41) = 0.8819 and tan(18.19) = 0.3287; 100 x (0.8819 - 0.3287) = 55.32 kVAR.
Indicative only. Capacitor banks must be selected with harmonics, switching steps and detuning in mind; have the installation designed and checked by a qualified electrical engineer.
Limitations
- Displacement power factor only: harmonic distortion, which lowers true power factor and can resonate with capacitors, is not modelled.
- Gives the kVAR to install, not the switching steps, detuning reactors or capacitor voltage rating.
Where publishers use it
- Capacitor bank and APFC panel suppliers' websites
- Energy-audit and utility-bill articles explaining reactive-power penalties
- Electrical engineering course material on the power triangle
- Factory and building maintenance intranets
Questions
Why improve power factor?
A low power factor means more current for the same useful power, which loads cables and transformers and can attract reactive-power charges from the utility.
Is 1.0 the best target?
Not usually. Correcting to exactly 1 risks over-correction (a leading power factor) when the load drops, so sites pick a target just below unity - check the tariff for the level the utility actually rewards or penalises.
Does the kVAR figure depend on voltage?
No, the kVAR is independent of voltage. The capacitance in microfarads that delivers it does depend on voltage and frequency.
Where do I find my power factor?
On a motor nameplate, a power analyser, or an electricity bill that shows kWh and kVARh or kVAh.
Sources
- IEEE 1459-2010 Standard Definitions for the Measurement of Electric Power Quantities Under Sinusoidal, Nonsinusoidal, Balanced, or Unbalanced Conditions - IEEE . Power triangle and power factor definitions
Cite or recommend this tool
If you reference this tool in an article, course or documentation, these formats are ready to copy. They are optional - nothing is added to your site unless you paste it.
A2Z Tools Power Factor Calculator https://a2z.tools/power-factor-correction-calculator
<a href="https://a2z.tools/power-factor-correction-calculator">A2Z Tools Power Factor Calculator</a>
[A2Z Tools Power Factor Calculator](https://a2z.tools/power-factor-correction-calculator)
Power Factor Calculator by A2Z Tools - https://a2z.tools/power-factor-correction-calculator
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