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Calcimator

Power Factor Correction Calculator

Calculate the capacitor bank size (KVAR) needed to improve power factor and estimate energy cost savings.

Inputs

kW

ANSI/IEEE Std 141: utility penalty typically <0.85–0.90 PF; target 0.95 for optimal; avoid leading PF >0.99

V

Results

Required Capacitor Bank

276.62 kVAR

Est. Annual Savings

6,600 $

Current Reactive Power440.96 kVAR
Target Reactive Power164.34 kVAR
I²R Loss Reduction37.67%
How to Use This Calculator
  1. Enter the Real Power (P) in kW — read from your utility bill or an energy meter.
  2. Enter the Current Power Factor from your utility bill or measured with a power analyzer. Most utilities charge penalties below 0.90.
  3. Enter the Target Power Factor — 0.95 is a common target; some utilities require 0.92 minimum.
  4. Enter the System Voltage in volts where the capacitor bank will be installed.
  5. Read the Required Capacitor Bank size in kVAR to order the correct capacitor equipment.
  6. Review the estimated Annual Savings — compare this to capacitor installation cost for a simple payback calculation.

How the result changes with Current Power Factor

Current Power FactorRequired Capacitor BankEst. Annual Savings
0.55596.88 kVAR11,669 $
0.67388.16 kVAR8,780 $
0.82185.96 kVAR4,499 $
0.9415.47 kVAR330 $

What each input means

Real Power (P)
Total real power consumption of the facility in kW.
Current Power Factor
Existing power factor before correction (from utility bill or measurement).
Target Power Factor
Desired power factor after correction. Most utilities require ≥ 0.90 per ANSI/IEEE Std 141 (Red Book) and utility tariffs; penalty typically assessed below 0.85–0.90. Target 0.95 for optimal KVA reduction without over-correction.
System Voltage
System voltage where capacitors will be installed.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Real Power (P) = 500, Current Power Factor = 0.75, Target Power Factor = 0.95, System Voltage = 480 = 4 input(s) provided
  2. Calculate Required Capacitor Bank
    Required Capacitor Bank = Math
    276.62 = 276.62
  3. Calculate Est. Annual Savings
    Est. Annual Savings = Math
    6600 = 6600
  4. Calculate Current Reactive Power
    Current Reactive Power
    440.96 = 440.96
  5. Calculate Target Reactive Power
    Target Reactive Power
    164.34 = 164.34

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