A measurement of the time phase difference between the voltage and current in an AC circuit. It is represented by the cosine of the angle of this phase difference. For an angle of 0 degrees, the power factor is 100% and the volt/amperes of the circuit are equal to the watts. (This is the ideal and an unrealistic situation.) Power factor is the ratio of Real Power-KW to total KVA or the ratio of actual power (watts) to apparent power (volt-amperes).