A kVAr calculation is a type of formula that works to determine the power factor. Power factor is a measurement electricity companies use to determine how much to charge a customer for his electricity usage. If the power factor for a facility is under 95 percent, the power company may assess a reactive power, or kVAr, fee to the customer.
When determining the power factor, those doing the calculation often use the power factor angle to get the necessary percentage. The person doing the calculation looks at the reactive power (kVAr), the real power (kW) and the apparent power (kVA).