Power Factor Correction Calculator
Capacitor kVAr needed to fix power factor.
Enter your values
Enter the real power in kW.
Enter the current power factor you are working with.
Enter the target power factor you are working with.
Enter the demand charge per kva in $.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Capacitor size needed
- 95.3 kVAr
- kVA before
- 208.3
- kVA after
- 157.9
- Monthly saving
- $403.51
Quick answer
Correction capacitors supply reactive power so the supply only carries real current.
kVAr = kW × (tanφ1 − tanφ2)
At a glance
| What it does | Capacitor kVAr needed to fix power factor. |
|---|---|
| Category | Engineering |
| Inputs needed | Real power, Current power factor, Target power factor, Demand charge per kVA |
| Main output | Capacitor size needed |
| Formula | kVAr = kW × (tanφ1 − tanφ2) |
| Cost | Free — no sign-up, no download |
How to use the Power Factor Correction Calculator
- 1Enter your real power load in kW.
- 2Enter current and target power factor.
- 3Add the demand charge to see savings.
Inputs explained
- Real power(kW)
- Enter the real power in kW.
- Current power factor
- Enter the current power factor you are working with.
- Target power factor
- Enter the target power factor you are working with.
- Demand charge per kVA($)
- Enter the demand charge per kva in $.
Worked example
Using the values the calculator loads with:
Inputs
- Real power150 kW
- Current power factor0.72
- Target power factor0.95
- Demand charge per kVA8 $
Results
- Capacitor size needed95.3 kVAr
- kVA before208.3
- kVA after157.9
- Monthly saving$403.51
Frequently asked questions
What target PF should I aim for?
0.95 is the usual utility threshold before penalties.
Can PF be over-corrected?
Yes — leading power factor causes its own problems and penalties.
What do I need to enter into the Power Factor Correction Calculator?
Just 4 values: real power, current power factor, target power factor, demand charge per kva. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Power Factor Correction Calculator work out the answer?
Correction capacitors supply reactive power so the supply only carries real current. It applies the formula kVAr = kW × (tanφ1 − tanφ2) and shows the working so you can check each step by hand.
Is the Power Factor Correction Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.