When wire is referred to by its gauge, it is a reference to the diameter of the wire. There are two standards of gauges generally used in jewelry to state the size of wire. American Wire Gauge (AWG, also known as Brown and Sharpe), and Standard Wire Gauge (SWG, also known as Imperial or British Wire gauge). The smaller the diameter of the wire, the bigger gauge number. For instance, a 20 gauge (AWG) wire is 0.0320 inches or 0.812 mm, and 12 gauge (AWG) is 0.0808 inches or 2.053 mm. AWG is slightly larger in size than SWG. 20 gauge in AWG is 0.0320 inches and 20 gauge in SWG is 0.036 inches.