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What Size Wire For 50 Amp?

50 ampere is one of the most public amperages for the fulfillment of the wire or a gauge or breaker.

The common questions that come into someone’s mind are what should be the length of wire when the amperage is 50 amps and voltage is 240 volts?

If you check the ampacity of wire gauges, you will get to know that there are three types of AWG sizes of wires that can be used for the installation of panels and sub-panels. The three types are :

  • A wire of 8 AWG has a 50A ampacity, which is too short.
  • 6 AWG that has a 65A ampacity which is just perfect.
  • A wire has 4 AWG with an ampacity of 85A, which is way too big for installation.

Now, if we take a look at the sizes of the wires, it may seem that choosing the 8 AWG that also has an ampacity of 50A is a good choice.

However, in most cases, the wire size that has 50 amps and 6 AWG will be considered correct. The reason behind this is the rule of 80% breaker ratings, which is set by an organization known as the National Electrical Code (NEC). This rule states that the maximum loading capacity on any circuit is 80%.

This article will provide you with the best instructions on NEC-generated rules and their sizes of wires.

This article will also be any query regarding adjustments you might require for the voltage drop, which can be elevated by the rise of the length of the wire. Let us take a peek at how to decide between different AWG wires suitable for 50 amps.

Wire of 50 Amp Size (Using NEC 80% Rule)

You want to avoid using a wire with a 50 A ampacity to create a 50 A  electrical circuit as if you ever do that(by accident or on purpose), you are most likely to burn up the whole circuit.

The 80% rule that has been introduced ensures the safety measures of humans and electric circuits. At least to cover the top, you should have that extra 20% of the 50A ampacity.

The calculations for the measurement of 50amp wire and its ampacity is as follows:
ampacity of wire for 50 amps= 50A/0.8 = 62.5a wire.

This indicates that you must use the wire with a capacity of handling 62.5A as a wire of 50amp. Now the situation that comes up is that you don’t have a 62.5A wire but instead have a 65A.

Note that if the wire is big, that will not make any difference, but if the wire is small, it will definitely be the reason for some issues. Most of the time, the perfect size of wire is 6 AWG for a breaker of 50 amps. In some of the limited cases, there comes the need for a larger wire of 4 AWG.

Wire size of 50 Amp 100+ Feet Away (Account For Voltage Drop)

Voltage drop plays a vital role even if you have a large wire and the electricity has to travel through a long distance. A rule of thumb that is considered suitable for the drop of voltage is;

For Every Distance Of Almost A 100 Feet, The Voltage Drops By 20 Percent.

If you are required to have the same wattage or power from the direct source of the sub-panel, which is 100 feet away, you need to elevate the amps by 20 percent to balance the drop that happened to the voltage by 20%.

That generated the meaning that the current flow is more than expected, and you require a bigger wire to fulfil the energy flow.

What Wire Size Do I Require For 50 Amp At 110-240V?

Voltage requires no bearing on the wire size; the only task it does is to determine the wires’ insulation and thickness.

A major mistake made during these times is thinking that all the wire sizes are identical and all work alike for different voltages. We don’t need to have a larger or smaller wire for 50 amp at 240 volts than for 50 amp at 110 volts.

Now when the sizes of the wire and amps may be the same. With the changing voltages, it is not necessary to have changed amps. We get a different rate of power (wattage).


All of the instructions, as mentioned earlier, and information were regarding the wire sizes for different amps and voltages. The passing of the current depends upon the wire that will be used, and to accomplish it, we need to choose the correct wire to avoid tripping and dropping voltage. You can always check the building codes if you need clarification about which wire you should use. After that, use the answers that are provided here. These are the easiest and safest answers, and the pro is that they are based on the latest instructions from National Electric Code Guidelines.

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