18 Gauge Wire Diameter

American wire gauge size calculator and chart. The following chart is a guideline of ampacity or copper wire current carrying capacity following the Handbook of Electronic Tables and Formulas for American Wire Gauge. When comparing gauges, the lower the gauge number, the thicker the wire.

Unless otherwise stated, the gauge for products on our site is calculated using the Standard Wire Gauge (SWG) system (also known as British or Imperial Wire Gauge). Both AWG and mm are basically a measure of wire diameter (thickness). AWG or American Wire Gauge is a diameter unit used predominantly in the US, while a metric mm (millimeters) is used around the world.

Diameter, Resistance and Maximum current listed for each AWG size. The AWG (American Wire Gauge) wire size chart with detailed specifications on wire diameter, resistance, and ampacity. Find conversions between AWG sizes and metric units for electrical and engineering applications.