In residential service calculations, demand factors are used to:

In residential service calculations, demand factors play a critical role in refining the total load calculation by acknowledging that not all appliances and systems will be in operation simultaneously at their maximum capacity. Demand factors are used to reduce the calculated load because they consider the likelihood of concurrent usage.

For example, while the total load of all appliances and devices in a house may sum up to a significant number, in reality, certain circuits will not draw their maximum load at the same time. By applying demand factors, the calculation aligns more closely with realistic operating conditions, allowing for a more cost-effective and efficient design of the electrical system. This approach helps in sizing the feeder and service correctly without oversizing the conductors, thereby reducing unnecessary costs and ensuring safety and efficiency.