Question: what is the difference between 12/2 wire and 14/2 wire?
Answer: 12-Gauge Vs 14-Gauge Wire A standard 12-gauge copper wire has a diameter of 2.05 mm, while the diameter of 14-gauge copper wire is only 1.63 mm. ... It's not quite as flexible as a 14-gauge wire, and it costs a bit more, but it's always a safe choice on a 15- or 20-amp circuit.