150 AMP Service: Wire Size Dilemma Solved (With Calculator+Tables)

Wondering about the right wire size for your 150 AMP service? We’ve got you covered.

For a 150 amp service, the recommended wire size is 1/0 gauge for copper and 2/0 gauge for aluminum or copper-clad aluminum wire. If your distance exceeds 50 feet, opt for 2 AWG copper wire. For grounding electrode conductors, use 6 AWG copper or 4 AWG aluminum wire.

However, wire size considerations can vary based on factors such as temperature rating, distance, and material. In this guide, we’ll dive into the various wire sizes for a 150-AMP service and provide additional insights to help you make the right choice.

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What is a 150 amp service?

150 amp is the capacity of the electrical service you have fixed in your homes. 

When you fix a 150 amp service for your home, the service can handle and give you only 150 amperes of current. 

Every house’s electrical services come with amp ratings. 

The old houses used to have 30-60 amp electrical services, which was enough at that time because there wasn’t as much electrical equipment as today. 

Some people also use 100-125 amp services because, according to their electrical appliances, it is enough.

On today’s date, you need at least 150 amp electrical service.

Amp ServiceTypical Use CasesRecommendations
30-60Older homes with minimal electrical equipmentConsider upgrading to 150-200
100-125Sufficient for many households with basic appliancesConsider 150-200 for more devices
150Suitable for modern lifestyles with multiple devicesUpgrade to 200 if needed
200Standard for houses with numerous electrical devicesSuitable for most households
Amp Service Comparison:

If you take more than that, it will be much better for you. 

200 amp is the standard one these days, but 150 is not a bad one after all. 

Why do people need it?

A 150 amp service is much better than 30,50, 100, and 125 amp electrical services.

With this service, you can easily have some common kitchen appliances, televisions, dishwashers, stereos, fans, and lights. 

However, it is inferior to 200 amp service.

200 amp service is a standard one, enough for houses with more electrical appliances. 

For people who live minimalist lives and want a bit cheaper service, 150 amp service is enough for them.

But, if you live a modern lifestyle with multiple electrical devices, opt for a 200 amp service.

Wire Size Calculator For 150 AMP

The wire size calculator helps you figure out what size wire you need for a 150 amp electrical circuit based on a few things:

  • How long the wire will be (in feet)
  • The voltage of the circuit (e.g. 120V or 220V)
  • How much of a voltage drop is allowed (according to NEC guidelines)

The calculator uses this information to figure out how many circular mils (CM) the wire needs to be in order to keep the voltage at an acceptable level over the distance. Then it matches that CM value to a suitable American Wire Gauge (AWG) wire size based on a chart.

150 Amp Wire Size Calculator

150 Amp Wire Size Calculator

Insert Wire Length, Voltage, And Allowed Voltage Drop Percentage (%), Get Wire Size For 150 Amps:

Recommended Wire Size for 150 Amps:

What wire size is needed for 150 amp service?

While you install a 150 amp service or upgrade your existing service to 150 amp, you must be aware of the wire sizes required for setting up the service.

The size of the wires may or may not differ depending on the service type. 

Generally, the best type of wire for 150 amp service is a 1-gauge copper wire. 

The size will differ depending on the situation. 

Whatever service you have, the size for hot and neutral wires is kept the same.

However, the ground wire will differ and doesn’t have to be the same as the other two kinds of wires. 

Wire material

There are two types of wires you can use - copper and aluminum.

The wire size will be different for the two different types of wires. 

The difference in wire sizes according to the wire materials is due to the conductivity and other features of the individual wires. 

Copper wire has high conductivity; thus, it can carry high electricity loads without issues.

That is why you can use smaller copper wire gauges.

Aluminum has low conductivity compared to copper wires.

So, you have to use higher gauges so that it can handle enough current loads. 

Temperature rating

You have noticed that I have mentioned two sizes in the case of aluminum wire.

Sometimes, the wire size can change based on the temperature ratings.

For example, 

The wire size for copper doesn't change much because copper can handle loads of electricity in smaller gauges without getting heated up. 

On the contrary, aluminum has poor conductivity, so you need higher gauges for 150 amp service at 167°F.

What is the wire size of 150 amp 300 feet away?

In 150 amp service, 1-gauge copper wire is enough.

If you want to run the service 300 feet away, a 1-gauge wire will be sufficient.

A 1-gauge copper wire can carry enough current and voltage for maximum appliances within this distance. 

For aluminum, go for a 2-gauge wire.

What is the wire size for a 150 amp sub panel or breaker?

If you are connecting a sub-panel or breaker in your house that can handle around 150 amps, then you can opt for 1/0 copper wire. 

If you plan to upgrade your older sub-panel or breaker to 150 amps, use copper around 3/4 inches longer.

It will ensure it can work better in your recent panel. 

If you cannot use a copper conductor, go for a 7/8-inch aluminum conductor instead. 

Also read: What Kind Of Wire Goes From Meter To Breaker Box?

What size of wire is needed for a 150 amp alternator?

If you use a 150 amp alternator, go for a 2 gauge wire, provided the distance is 4-7 feet away from the alternator. 

You may use a bigger gauge, up to 1/0 gauge, if the distance is more than 7 feet.

What are the different wire types?

If you have read so far, you have come across some wire material types, copper, aluminum, and copper-clad aluminum.

These are the three common types of wires used for electrical purposes. 

Let's see the benefits and drawbacks of these wires and why people prefer them. 

Copper wiring

Copper wires are considered the best type of wire for electrical wiring purposes.

They can carry loads of electricity without getting heated up. 

Though the product is very expensive, it will give you a lot of benefits. 

Here are some great advantages of using copper wire:

  • The copper wires are excellent conductors of electricity. It can carry loads of electricity without getting heated up. Since it is a good conductor, you can work with smaller copper wires without any issues.
  • The copper wires are thinner and don't contract or expand. So, the electricity flow doesn't get interrupted, and you can use them for longer distances. 
  • Copper has Patina, a green tarnish that oxidizes and changes the wire color. It makes them corrosion-resistant. 
  • Since the wires are thin and malleable, you can mold, bend, and use them without the risk of breakage. 

However, some people cannot afford copper as they are very expensive. 

Since copper wires have high conductivity, 1 AWG will be enough for 150 amps.

Aluminum wiring

Aluminum wiring is a good choice for people who cannot afford copper. 

But, aluminum has some drawbacks compared to copper, which doesn't have many drawbacks except for the price. 

Some disadvantages of aluminum are:

  • Aluminum is a poor conductor of electricity. It cannot hold loads of electricity. 
  • The wire can get heated up easily if the current flow is too much to handle. As a result, you might have to face a fire hazard. 
  • Aluminum wires do not have tarnish or anything and do not change color. So, they are not corrosion resistant either. 
  • The wires contract and expand. So, the current flow might get interrupted during certain situations. 

However, you can adjust these things by using a higher gauge, nearly double the size of copper. 

If you use 1 AWG copper, you will have to use 2 or 3 AWG aluminum for 150 amps. 

However, despite these drawbacks, people still prefer aluminum because:

Aluminum is very cheap compared to copper wires.

So, you can easily get higher gauges and use them without any issues. 

Aluminum wires are very lightweight.

Installing them is faster and handling them is easier. 

If you want to use aluminum wires at 167°F, use a 3 AWG wire.

At 194°F temperature ratings, use 2 AWG aluminum. 

Since it has many drawbacks, you might have to do some fittings to adjust the issues.

Or, you can use copper-clad aluminum. 

Copper-clad aluminum

Copper-clad aluminum is cheaper than copper but more costly than aluminum.

This wire has some copper fittings at its ends, giving some copper benefits. 

You can call it to be an upgraded version of aluminum. 

Copper-clad are not as good conductors as pure copper but are better than aluminum. 

The size of the wires, however, will be the same as aluminum wires, 2 or 3 AWG.

Is 150 amp service enough?

A house with 150 amp service is enough for a single house.

The member/s of the house can easily run the common household appliances with this service. 

You will need an electrician for guidance to understand the exact amp service. 

Neither a smaller nor a higher amp service is good for your house. 

In a less amp, the electricity load will be too much, and it might cause a fire hazard. 

At the same time, if the service is higher, it will lead to crackled outlets, light dimming, plugs with scorch marks, breakers tripping, etc.

How can I receive 150 amp service for my house?

To get a 150 amp service, you cannot do it on your own if you don't have any experience or your state doesn't have permission to get such tricky jobs done by natives. 

You must contact the electrician or utility provider to upgrade or replace the service. 

You can also consult a third party, especially an experienced contractor, to do the job.

But they must have the permission and required tools to do the job. 

Also read: Who Is Responsible For Power Line From Pole To House? (Installation+Maintainance)

How much will the installation and upgrade cost?

Generally, a 150 amp service will cost around $85-360.

It is the panel cost and not the installation or upgrade cost. 

To replace the service, expect the cost to be around $2000-3000.

You will also need a circuit breaker which will cost around $200-300, and a meter box around $500-700. 

The labor cost will be around $40-100, depending on the working hours and job complicacy. 

Expenses HeadApprox Value
Panel cost$360
An average hour to work14 hours
Labor cost$70
The total average cost$1340
Here is a table explaining the upgrade cost.

How to install a 150 amp service?

Installing a 150 amp service is not different from installing the other services. 

In simple words, remove the distribution equipment, i.e., the old socket and main disconnect.

Then, set up the new meter socket, main disconnect, utility pull section, and new distribution equipment; everything appropriate for 150 amp service.

Wire size chart

To help you understand the wire size of different services, below I have shared a small table with different amperes and the wire sizes:

Services in amperes Wire size (copper)Wire size (aluminum or copper-clad)
100 amps#4 AWG#2 AWG
110 amps#3 AWG#1 AWG
125 amps#2 AWG#1 AWG
150 amps#1 AWG#2 AWG
175 amps#1/0 AWG#3/0 AWG
200 amps#2/0 AWG#4/0 AWG
Properly sizing the wire for your 150 amp service is not only about meeting electrical code requirements but also about ensuring the safety of your home and the efficiency of your electrical system

Final words

The best size of wire for 150 amp is 1 AWG copper or 2 AWG aluminum or copper-clad aluminum. If the temperature is around 194°F, use a 3 AWG aluminum wire gauge. 

The size of the wire should be around 1-1/4th inch wide.  

The right size for hot and neutral wires is 1 AWG copper or 2 AWG aluminum. For the ground wires, it is 6 AWG copper or 4 AWG aluminum.

Both copper and aluminum are good wires, but copper is the best. Though it is costly, it has a lot of advantages. If you can’t afford it at all but want good wires, you can try copper-clad aluminum.

Also read:


How do I know that I am having a 150 amp service?

Open the main service panel and check the circuit breaker labeled with a number. If it is written 150, you have a 150 amp service.

The fuse panel will have a main fuse block with the same information. 

How many breakers do you need for 150 amp service?

In old times, the NEC recommended needing 42 circuit breakers.

But in the present time, the data printed by the manufacturer inside the panel doors will have a number.

It will tell you the number of breakers a 150 amp has. 

Why do the 150 amp services disconnect?

If the breaker keeps tripping, it means you have an overloaded service.

In that case, the lights keep dimming or buzzing.

If it isn’t, check for ground faults or short circuits.

Use the electrical disconnect to shut down the main power and call an electrician to fix the situation.

Data Source: National Electrical Code

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Arthur Smith

Howdy! I am Arthur Smith, an electrical engineer who is extremely passionate about electronics. I have lived in different parts of the US and currently reside in Wisconsin. I am one of those rare children who knew what he wanted to study and do in life right from the start. I was a curious child who wanted to know how switches work and how the AC works, and I would always observe my dad whenever he would handle the wires and fix things around the house. I currently work as an electrical engineer at a reputed company and write for this blog. And I read loads of books or play video games in my free time.

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