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ElectricalMay 9, 2026|3 min read

Power Factor

Power Factor is a core engineering term. Definition, usage notes, and a practical example.

Definition

Power factor is the ratio of real power to apparent power.

Why it matters

It is used in AC motor and facility power quality calculations.

How it is used

In a design check, first define the relevant load, dimension, material, or flow condition. Then interpret this term by its role in the formula and compare it with limits.

Basic expression

Power factor = real power / apparent power

Example

Low power factor can require higher current for the same real power.

Formulas

Basic expression
Power factor = real power / apparent power