 Power Factor is a measure that allows an operator to make sure the power coming into their facility is in phase. It is calculated at the ratio of real power to apparent power. A power factor of less than one means that the voltage and the current waveforms are not in phase. Power factors seem like a difficult concept, but it's actually very simple. Let's break down the concept of power factor now with something almost everyone loves, pizza. This part of the pizza here is the part with the good stuff. It has all the toppings, cheese, and sauce. The stuff that really makes a pizza a pizza. In our analogy, this represents real power. Real power is the power that is used to power equipment in order to complete important work. Just like the toppings are important to making a good pizza, real power is important to making sure things get done in a facility. However, that's only part of what we're dealing with. The pizza also has a crust. While it is often consumed, there are a lot of people that just want to throw it away. Without the toppings, it can be seen as quite a useless part of the pizza. This represents reactive power. Reactive power can be considered as current that arrives either too late or too early and does not perform useful work. The entire slice, toppings and crust, can be consumed. Just like a mission critical facility consumes real and reactive power. The slice is representative of apparent power, which is the total amount of power consumed by a facility. So power is calculated as the ratio of real power to apparent power, or the useful power that is consumed to the total amount of power that is consumed. With our pizza analogy, it is the ratio of the part with the toppings to the entire slice. The bigger the area with the toppings is, the more desirable the slice of pizza. Just like the more useful power a facility has, the better the power factor is in an organization.