What unit of measurement is used for power factor?

The power factor is a dimensionless quantity that represents the ratio of real power flowing to the load, to the apparent power in the circuit. It measures how effectively electrical power is being converted into useful work output. Since it is a ratio, the unit cancels out, resulting in a dimensionless number typically expressed as a value between 0 and 1, or as a percentage. A power factor of 1 indicates all the power is being effectively converted into work, while a lower power factor indicates that some power is wasted.

In contrast, watt is a unit of measurement for real power, volt measures electric potential, and amp refers to electric current. These terms are specific to quantities of energy or flow, but they do not describe the efficiency or effectiveness of power usage as power factor does. This distinction clearly defines why the appropriate answer is that the power factor is dimensionless.