Working with Wire
The term ‘gauge’ is used to define the diameter of the wire. The gauge of a wire is used to determine the amount of current a wire can safely handle. Wire gauge can refer to both electrical and mechanical. This tutorial will only cover electrical. There are two main systems for measuring gauge, American Wire Gauge (AWG) and Standard Wire Gauge (SWG). The differences between the two are not critical to this guide.
An approximate scale of several different gauges of wire
The amount of current that a wire can carry depends on a few different factors, for example the composition of the wire, wire length, and condition of the wire. In general, thicker wire can carry more current.
An approximate wire thickness to current capability chart
Here at SparkFun we typically use 22 AWG wire for prototyping and breadboarding. When using a breadboard, the solid core is perfect because it fits nicely into the breadboard holes. For other prototyping/building involving soldering, the stranded core is #1, just be sure not to let too much current run through a single wire, it will get hot and could melt!
SparkFun carries a variety of both solid and stranded 22 AWG wire. Check it out!