What Size Wire for My Breaker Do I Need? [20, 30, 40, 50, 60]

Picking the right wire size is important irrespective of the 30 amp or a 40 amp breaker you might plan to use it with.

Wire is sold based on various factors. One of which is the gauge, also known as American Wire Gauge (AWG).

Gauge refers to the measurement of a wire, specifically its diameter. In the United States and some parts of the world, AWG is the standardized system of measurement.

Wire gauge is measured from high to low with higher numbers measuring a smaller wire size.

Correct wire sizing is crucial for circuit breakers since it helps determine how much electrical current can flow through it and how much resistance it has.

The chart below shows what wire size is required for the amount of power that will be running through the line.

Note: The information contained in this article is a general guideline. For more questions, always consult a certified electrician, as well as your local electrical codes.

Wire Size Ampacity Chart

The chart below outlines what gauge wire you need for the maximum amperage, or strength, of the electrical current.

The gauge can sometimes range between copper and aluminum wires.

Below is the gauge size based on the more commonly used copper wires:

It is recommended to always check the amp of an appliance before use.

You can calculate this by dividing Watts by volts.

10 Amp Wire Size

A wire gauge of 16 is needed for a maximum of 10 amps.

Common appliances that need around 10 amps typically consist of:

• A radiator
• A toaster
• A hair dryer
• A washing machine
• A dishwasher
• A vacuum cleaner, and
• A dishwasher

What about 30 amp wire size?

30 Amp Wire Size

A wire gauge of 10 is needed for a maximum of 30 amps.

The common household item that needs a 30 amp circuit is a central air conditioner.

People living in RVs use 30, and sometimes 50, amp systems to run all appliances in their vehicle too.

What about 40 amp wire size?

40 Amp Wire Size

A wire gauge of 8 is needed for a maximum of 40 amps.

A lot of electric cooking appliances in your home require this.

A common one is the electric cooktops

50 Amp Wire Size – What Size Wire Do You Need for a 50-Amp Breaker?

The maximum wire size for 50 amp breaker is 6. You’ll need a wire gauge of 6 for a maximum of 50 amps. The 6-gauge copper conductor wire is rated up to 55 amps, making it the perfect choice for this circuit.

Fifty amp breakers are most often used to power many different appliances. However, a kitchen oven can alone require 50 amps.

Many electric dryers also require a 50-amp breaker.

50 Amp Wire Size (Using NEC 80% Rule)

A 50A ampacity wire cannot be used to create 50 amp electric circuit. An attempt at that will dry your circuit.

The 80% rule by NEC serves as a safety measure. You should at least have that additional 20% on top of 50A ampacity.

Here is how to calculate at least how much ampacity a 50 amp wire should have:

Wire Ampacity For 50 Amps = 50A / 0.8 = 62.5A Wire

That means you need to use a wire that can handle 62.5A as a 50 amps wire. Now, since 62.5A wire does not exist, yet, the closest wire we have to it is the 6 AWG wire with 65A ampacity.

While it is fine to use a bigger wire, a smaller wire is never advised. For 50 amps, you might opt to use 4 AW wire with 85A ampacity (a bit too much but it’s fine), but you should never use 8 AWG wire with 50A ampacity (that will cause the circuit to fry).

As far as we can tell, 6 AWG is an almost perfect sized wire for a 50 amp breaker. In limited cases, you might have to use a larger 4 AWG wire.

That’s when you have a long circuit and are sending electrical current at some distance (100 feet or more).

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

It is smart to always account for voltage drop when sending electricity through a long distance.

For instance, sending electricity to a 50 amp sub panel 100 feet away.

A good practice for voltage drop is this:

For every 100 feet, voltage drops by 20%.

In order to get the same power (wattage) at the sub panel 100 feet away. You will need to increase the amps by 20% (to balance out the 20% drop in voltage).

That, of course, means you will need a bigger-sized wire since you’re dealing with more amperes (more current).

Example: 50 amp wire is usually the 6 AWG (we require at least 62.5A and 6 AWG can handle 65A). If you have to power an electric device 100 feet away, you need 20% amps more. Instead of 62.5A, you’re looking at 62.5A × 1.2 = 75A.

In this case, the 6 AWG gauge wire with 65A is insufficient. A 75A is the minimum for good function here. The next wire size that can handle more than 75A is the 4 AWG gauge. This one can handle at 85A and is typically used as a 50 amp wire size for 100 feet away sub panels.

Yes, we know there are loads of questions relating to 50 amp and various voltages.

Let’s tackle this one as well:

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

A popular myth regarding 50 amp wire is that we need different wire sizes for different voltages. No, that is not true.

We don’t need a smaller (or bigger) wire size for 50 amp at 240V than for 50 amp at 110V, for instance:

In all cases (with the exception when we need to account for voltage loss) we use 6 AWG wire for 50 amps.

Now, the wire size and amps might be the same. But, with different voltages, we don’t get different amps; we get different power (wattage).

What Gauge Wire For 50 amp 220V?

For instance, a 50 amp wire on a 220-volt circuit (using a 6 AWG wire) can handle up to 11,000W of power (this is very common electricity setting for most RVs).

Calculation is simple. Here’s how:

Wattage = Amps × Volts = 50A × 220V = 11,000W

If you have a 110V circuit, the 50 amps will produce 5,500W of power.

We hope the topic of 50 amp wire sizes has been made simple to understand and clearer now.

What Gauge Wire Can Handle 50-Amps?

Can 2 10 Gauge Wire Handle 50-Amps?

Yes, 3 gauge wire is thicker than 6AWG wire and can handle 50 amps. The minimum requirement to run a 50A circuit is 6-gauge wire.

There is no harm in using a thicker wire like 2-gauge. Yes, it costs more, but it will give better value in the long run.

Can 4 Gauge Wire Handle 50-Amps?

6AWG can handle 50 amps, but 4AWG is larger. Therefore, it can conveniently handle 50-amps better than 6-gauge wire.

Can 6 Gauge Wire Handle 50-Amps?

Yes, It is most commonly recommended to handle 50-amps.

Can 8 Gauge Wire Handle 50-Amps?

I wouldn’t recommend it since it is thinner and will melt under high temperatures. A 8 gauge wire will melt when it hits temperatures of 90 degrees C. This can lead to a fire outbreak.

Can 10-Gauge Wire Handle 50-Amps?

Like 8 gauge, do not use a 10-gauge to carry 50 amps. The current passing through will heat the cables to a point where they melt, causing a short circuit and starting fires.

Can 12 Gauge Wire Handle 50-Amps?

No, it cannot. The wire will overheat. You may get away with 12AWG if the wire is very short. But even then, you cannot use it for long. 12AWG conductors work with 20A circuits. 50A is too much. You will most likely start a fire. The practice is not safe. At the very least, it violates the NEC.

Wire Size For 50 Amps 240 Volts?

A wire gauge of 6 is required for 50 amps 240 Volts

What Size Wire For 50 Amps At 150 Feet?

To run 50 amps at 150 feet, you need No. 4 AWG.

What Size Wire For 50 Amps At 50 Feet?

At 50 feet, you will need a wire gauge of 6.

What Gauge Wire For 50 Amp 220v?

A wire gauge of 6 is required for 50 amps 220 Volts.

What Size Wire For 50 Amps At 100 Feet?

You’ll need 6 AWG at 100 feet. For every 100 feet, voltage drops by 20%.

What Size Wire For 50 Amps At 75 Feet?

You’ll need 6 AWG at 75 feet. For every 100 feet, voltage drops by 20%.

What Size Wire For 50 Amp Rv Service?

The best size wire for 50 amp RV service is a 6 AWG wire. You can use a 4 AWG wire for longer runs.

Whether you have a 30 amp, 40 amp or a 50 amp breaker, picking the correct wire size is essential.

Aluminum Wire Size For 50 Amp Breaker

13.3 aluminium wire size needs 5 gauge for 50 amp breaker.

What Size Wire For 50 Amp Double Pole Breaker?

The minimum wire gauge for a 50-amp breaker is eight gauge, and if the current draw is expected to remain close to the 50-amp limit for an extended period, you should use six-gauge wire.

What size wire is needed for a 50 amp breaker at a run of 145 feet?

#6AWG has 26000 circular mils and copper has an Ohmic value of 10.3 Ohms per circular Mill foot or 0.097 Siemens per circular Mill foot, the resistance of the run, out and back is 0.115 Ohms for a voltage drop of 5.75 volts at 50 Amps. 110volts is acceptable at -5%. 288 Watts will not damage 290 feet of #6AWG wire. a watt per foot is not much.

How to Read Cable Labels

While anyone can walk into a store and purchase wires in cables, not everyone is able to read product labels in other to purchase the correct product.

Here’s a quick look at what to remember:

First, you can find the AWG of the wire(s) in the cable. So, for a 16 gauge wire, it will read “16.”

Second, you may see an extra number. This could read in either of these 2 formats: “16-2” or “16/2.”

This number signifies the amount of service conductors or wires in the cable(s).

Lastly, you may see a “G” or “w/G.” Both mean that the cable comes with a ground wire, which does not count towards the total number of wires noted on the label already.

Circuit Breakers

You should determine the correct current draw when updating an air conditioner or home appliance.

If your circuit breaker is 20 amps, you simply cannot install an electronic that requires 30 amps. It is not as easy as just changing the circuit breaker. The wiring to the appliance needs to be changed too.

BUT! If the opposite occurs, the solution is easier.

For instance, let’s say you were using an appliance that requires only 30 amps. If you replace this with a 20 amps new appliance, you’ll need to change the circuit breaker and outlet receptacle – but you do not need to change the wire.

This is because a wire can safely carry less power than it was rated for without any potential issues. Butr, a wire cannot carry more power than it was rated for, otherwise it could get hot and create a fire hazard.

Other Aspects To Consider

Wire length:

Some situations might warrant the use of a larger wire size even if the amp requirement does not appear to demand for it.

Go the next largest wire size if your run is more than 100 feet, inside a conduit, or ganged with other wires where the heat dissipation may be affected.

As with all electrical work, consult a professional with any questions about special circumstances.

Wire material:

Using a wire that is not made of silver, brass, or copper might warrant you checking in to confirm if a different size will be needed or not.

Aluminum wires are much less common than copper ones, and they also vary from them in requirements: They offer 61% of the conductivity of copper wires but have only 30% of the weight of copper.

What Will Happen with The Wrong Size Wire?

You should never use a wrong size of wire. The use of a smaller gauge than needed could cause the wire to overheat and melt; making the appliance or breaker suffer damage and a potential fire hazard.

Using a wire that has a larger gauge than needed is not dangerous. Yes, it can be an inconvenience, since a larger wire is usually heavier and stuffer, but it won’t cause any harm or potential hazards.

Finding the right wire size is an essential step to any electrical project or circuit breaker set-up. It’s especially important to remember that it’s about more than just the number — remember to consider all the possible factors when it comes to wire gauge. The information in this article is only a guide — we highly recommend that you consult with your electrician, and check your local and national electrical codes, before purchasing and installing wires.