What is the formula for calculating power factor?

The formula for calculating power factor is derived from the relationship between active power, apparent power, and reactive power in an electrical system. Active power, measured in watts (W), represents the actual power consumed to perform useful work. Apparent power, measured in volt-amperes (VA), represents the total power flowing in the circuit, which includes both the active and reactive components.

Power factor is defined as the ratio of active power to apparent power. A power factor of 1 (or 100%) indicates that all the power is being effectively converted into work, while a lower power factor indicates that some of the power is reactive and not contributing to useful work. Thus, the correct formula for calculating power factor, which assesses the efficiency of the power usage, is active power divided by apparent power.

In contrast, the other options do not accurately reflect the calculation of power factor. For instance, apparent power divided by active power does not provide a meaningful measure of power factor. Real power divided by reactive power would not yield power factor but rather a different ratio that does not focus on the efficiency of power utilization. Lastly, peak kW divided by peak kVA is not a standard way to define power factor, which is conventionally expressed using