Wire Gauge 101: What Wire Gauge Do I Need For My Projects?

As wire gauge increases, the diameter of the wire decreases. This happens because the wire gauge system was originally based on how many times the conductive material was drawn through wire-cutting dies, a process that reduces the thickness of the wire. Essentially, the more times the wire is pulled through the dies, the thinner it becomes.

Thicker wires, much like a wider hose, allow electricity to flow more easily because they offer less resistance to the flow of current. Think of it as how a wider hose lets water flow with less pressure required. In electrical terms, thicker wires allow more current to pass through them without overheating or losing energy as heat.

This is why it is crucial to ensure that the gauge of wire you choose is adequate for the current it will be carrying. Using wire that's too thin for the amount of current being supplied can lead to several undesirable outcomes, which, as you can imagine, might include things like overheating, short circuits, fire hazards, or even damage to connected devices.

Improper wire gauge selection isn't just a technical detail—it's a critical safety consideration. Always ensure the wire is capable of handling the amperage (amount of current) and voltage for your specific application.

This is a reference table based on my application of these wires for systems.

All of this is based on residential/commercial applications

Important Considerations

Understand the Load (Amperage Requirements)

The first step is determining the current (amperage) that will pass through the wire. This depends on the appliance or device you are powering.

• Check the device's specifications: Each appliance or device should list the amperage or wattage requirement. For example, if a device requires 1,500 watts and the voltage is 120V, you can calculate the amperage:

  Amperage=WattageVoltage=1500W120V=12.5 amps\text{Amperage} = \frac{\text{Wattage}}{\text{Voltage}} = \frac{1500W}{120V} = 12.5 \text{ amps}Amperage=VoltageWattage​=120V1500W​=12.5 amps

• Use the wire gauge chart above: Once you know the amperage, refer to the wire gauge chart to find the appropriate gauge. As a general rule:

  • 14 AWG is good for circuits up to 15 amps.

  • 12 AWG is good for circuits up to 20 amps.

  • 10 AWG is good for circuits up to 30 amps, etc.

Consider the Distance (Voltage Drop)

When electricity travels over a long distance, some voltage is lost due to resistance in the wire, known as voltage drop. This can affect the performance of your devices. For long runs, you need to select a thicker wire to minimize this loss.

• Shorter runs: For typical residential or light commercial applications (less than 50 feet), voltage drop is usually negligible, and the standard gauge sizes are sufficient.

• Longer runs: For distances over 100 feet, you might need to choose a larger gauge wire (such as 10 AWG instead of 12 AWG) to compensate for voltage drop. This is especially important for high-power appliances (like air conditioners or electric dryers) or low-voltage systems (like outdoor lighting).

Make sure the correct wire is terminated.