What is the standard wire size for residential lighting circuits?

The standard wire size for residential lighting circuits is 14 AWG. This is because 14 AWG wire is adequately rated for typical household circuit applications, which generally require a 15 amp circuit breaker. Lighting circuits typically do not draw as much current as circuits for outlets or appliances, making 14 AWG wire suitable and safe for these loads. It provides a good balance between flexibility for installation and the ability to safely carry the electrical load associated with typical lighting fixtures without overheating.

Using a smaller wire size like 16 AWG would not meet the requirements for the current typically found in residential lighting circuits and could pose safety hazards due to potential overheating. On the other hand, while 12 AWG wire is often used for 20 amp circuits (such as outlets), it is heavier and less flexible than necessary for lighting applications. 10 AWG is even thicker and designed for much higher current capacities, which is unnecessary for lighting circuits and can complicate installation due to its rigidity. Hence, 14 AWG is the appropriate standard size for most residential lighting circuits.