What is the diameter of bell wire?

The diameter of bell wire typically ranges from 18 to 22 American Wire Gauge (AWG), which corresponds to approximately 1.02 mm to 0.64 mm in diameter. The most common size used for residential doorbells is 18 AWG, which has a diameter of about 1.02 mm. This wire is designed to carry low voltage, usually around 8 to 24 volts.