When choosing the right wire for a particular electrical project, it is important to consider its diameter. A wire’s diameter determines how much current (or amperage) it can safely carry before overheating and posing a fire hazard. In addition, a thinner wire is usually less expensive than a thicker one, making it the preferred choice for many projects. The best way to measure a wire’s diameter is to use a gauge. However, if you don’t have a wire gauge, it may be difficult to know how big or small a particular wire is. Fortunately, there are simple formulas that can be used to calculate the diameter of any given wire.
In the United States, the standard for wire size is American Wire Gauge, or AWG. This system uses numbers to represent the wire’s diameter and was first introduced in 1857. It is similar to the British Standard Wire Gauge, or SWG, and the Metric Wire Gauge, or MWG. Unlike these two systems, AWG does not take into account the thickness of the wire’s insulation or jacketing.
The higher the AWG number, the smaller the wire. In other words, AWG is a ratio of wire diameter to the number of its strands. However, it is important to note that AWG does not indicate a wire’s current-carrying capacity. This capacity is determined by the wire’s size and properties, including its conductivity.
In addition to its diameter, AWG also indicates a wire’s cross-sectional area. This can be calculated using a simple formula: the wire’s diameter is equal to its radius squared, multiplied by pi (pi is 3.14). The cross-sectional area of a wire doubles every time its gauge decreases by six levels (e.g., a three-gauge wire has double the cross-sectional area of a nine-gauge wire).
For most purposes, a wire’s diameter and ampacity are enough to determine which type is best for a specific application. For example, a thin copper wire is good for many light-duty electrical applications, while thicker cables are suitable for heavier-duty electrical work. In any case, it is always a good idea to choose a wire with an ampacity that is larger than the maximum amount of power the circuit will be carrying.
The chart above shows awg wire sizes and their corresponding amp capacities. Keep in mind that this chart is for bare copper wire, and that different types of insulated wire will have their own ratings. For instance, a stranded copper wire will have a different ampacity than a solid copper wire, and the rating will change depending on the length of the cable or the application. In any event, the chart is a helpful tool for selecting the proper wire for any application. For example, a wire with a high ampacity is ideal for running a generator because it will be able to handle more power than a lower-rated wire. Moreover, a lower-rated wire might overheat if it is subjected to too much current. awg wire size chart