Wire Size Calculator (AWG)
Ensure the safety and efficiency of your electrical circuits. This tool helps you select the correct American Wire Gauge (AWG) based on your system's voltage, current, and distance, while keeping voltage drop in check.
Why Wire Size is Critical for Electrical Safety
Choosing the correct wire size is one of the most important decisions in electrical design. A wire that is too small for the current it carries can be extremely dangerous. As electricity flows through a wire, it encounters resistance, which generates heat. If the wire is too thin, this heat can build up, melting the wire's insulation and creating a significant fire hazard. Furthermore, undersized wires lead to "voltage drop," a decrease in electrical pressure from the source to the device, which can cause motors to overheat, lights to dim, and electronics to malfunction.
Understanding Voltage Drop
Voltage drop is the loss of voltage along the length of a wire. The longer the wire, the greater the resistance, and therefore the greater the voltage drop. The National Electrical Code (NEC) in the USA recommends that the voltage drop for a circuit should not exceed 3%. This ensures that appliances receive enough voltage to operate correctly and safely. This calculator automatically checks the voltage drop for you, recommending the smallest possible wire gauge that keeps the drop below this critical 3% threshold.