A wire gauge chart helps you determine the wire gauge that matches the amps you need for the project. When purchasing wire, you'll see a few different numbers on the packaging or product description.

“Twelve-gauge wire is good for 20 amps, ... (NFPA 70) Table 310.15(B)(16) in detail, but as an example, according to this NEC chart, a 6-gauge copper circuit rated at 90°C (194°F) has an ampacity of ...