What Size Sub Panel For Basement? (+Estimated Cost)

Sub-panels in the basements help you run electrical appliances smoothly. Breakers are not enough because a basement will have multiple types of equipment. So, the right sub-panel size for the basement will depend on the number of appliances running. 

Generally, the basement’s average sub-panel size will be around 100 to 125 amps. That would cost around $400 to $600. You can also install a 60 amp sub-panel based on the appliances you have in your basement. A smaller sub-panel can reduce the installation cost. 

The cost may increase or decrease depending on several factors, like labor per hour, wire cost, work challenges, etc. A sub-panel is not compulsory, but having one allows you to run electrical appliances smoothly.

Does the basement need a sub-panel?

A basement is an underground floor inside the building. 

It allows you to have extra storage for all types of materials without comprising your house’s indoor or outdoor space.

When you think of wiring the basement of your house, you need to install a sub-panel due to the number of appliances. 

A sub-panel works as an extension of your main electrical panel that is the main panel. 

If you install too many appliances, the main panel size becomes insufficient to handle. 

So, installing a sub-panel will give the appliances enough power and keep everything safe. 

Sometimes, there is little space left for some extra lights and plugs. 

A sub-panel can help you with that.

How to determine the size of the sub-panel for the basement?

To know the right size of the sub-panel, you need to know what you will add to the basement. 

You can use a lower amp sub-panel for lighter appliances, like some light fixtures and outlets.

But if you have heavier appliances, like washers, computers, or furnaces, you need a sub-panel with a higher amp.

You have to know the wattage of the appliances and the number of amps they draw. 

If you need help understanding, consult an electrician to know the right sub-panel size. 

What size of sub-panel do I need for the basement?

Some new houses have 200 amp breaker boxes to handle the newly finished basements. 

Some appliances with their breakers in the basement include:

  • 2 regular outlet circuits rated at 20 amps
  • 2 GFCI (Ground Fault Circuit Interrupter) protected circuits rating at 20 amps
  • 2 light circuits rated at 15 amps
  • 1 optional electric heat circuit needs a double 20 amp breaker taking 2 spaces in the panel

If you want to have these things in your sub-panel, you can add up a 100 amp sub-panel or 125 amp sub-panel.

Some people do not use any electrical appliances in the basement except for some lights and outlets. 

For that, you can have 60 amps sub-panel.

It completely depends on how much wattage you receive from the number of appliances you have added to the basement. 

You can add as low as 60 amps or as high as 125 amp sub-panel. 

You can also use a higher amp, around 200 amps, depending on the appliances, for example, washers, furnaces, or dryers. 

But, they also must have their own breaker. 

The more appliances you have, the more power they will draw. 

To keep them running smoothly, you must use a higher amp sub-panel. 

There is nothing wrong with installing a bigger panel. 

It is always better. 

A bigger sub-panel will make the appliances run smoothly and allow you to add more appliances in the future. 

An experienced electrician can help you get the right size of sub-panel for your basement. 

What size of wire is needed for the sub-panel?

The amp rating will tell the wire size for your basement’s sub-panel. 

If you have a 100 amp sub-panel, you will require a 4 gauge wire to run the panel. 

A sub-panel will have separate neutral and ground wires. 

In that sense, you can have 4 gauge hot and neutral wires and a 6 gauge ground wire.

Here is a list of wire sizes depending on the sub-panel size:

Sub-panel sizeWire size
60 amp6 gauge copper or 4 gauge aluminum
100 amp4 gauge copper or 2 gauge aluminum
125 amp1 gauge copper or 1/0 or 2 gauge aluminum

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You can use an oversized wire without any issues. 

A thicker gauge keeps the voltage drop and resistance low and helps the appliances run smoothly. 

On the contrary, a thinner and smaller wire can melt and start a fire. 

What is the cost of installing a sub-panel in the basement?

The cost varies based on multiple factors like location, labor, wire, sub-panel cost, and work challenges. 

If you run any underground lines, that can cost nearly $3,000.

Otherwise, the average cost to install one complete sub-panel in the basement ranges from around $400 to $550. 

Including the labor and materials, installing a single sub-panel can cost between $500 and $1,300. It usually takes three hours to install.

Sometimes, the cost can reach up to $1,750 if you install a sub-panel between 100 and 150 amps with 4 to 20 circuits. 

So, expect the following cost of a sub-panel installation according to the amperage rating:

Amperage ratingCost of a sub-panel
60 amps$400 to $550
100 amps$400 to $1,000
125 amps$1,000 to $1,250
150 amps$1,000 to $1,750
200 amps$1,800 – $2,500

The price can increase or decrease due to the following factors:


The cost of the sub-panel size will affect the price first. 

Different sub-panel sizes will have different prices, for example

Sub-panel sizesCost
100 amp$100 to $200
150 amp$150 to $250
200 amp$250 to $350

Wire cost

Two wires are mainly used for electrical purposes – copper and aluminum.

Copper wires are thicker and good in conductivity, resistance, and strength. 

That is why they are costly. 

On the contrary, aluminum wires are thinner and less good in conductivity and resistance. 

Aluminum wires are good for shorter distances but not longer ones. 

So, they are cheaper than copper wires. 

However, you can get good results from copper-clad aluminum wires and save money. 

They have copper fittings that give some copper benefits.

Along with the material, the distance will also affect the cost. 

For example, a 2 gauge copper wire for 1000 feet can cost around $1,600. 

So, the wire cost can highly increase the average cost of sub-panel installation. 

Labor cost

The labor cost depends on the work challenge. 

Generally, the labor cost remains between $50 and $100. 

Sometimes, it can be between $100 and $200. 

What size of breaker is needed for the basement?

The basement lights can be on the general-purpose circuit, measuring 15 or 20-amp breakers. 

But, if you use any heavy appliances like a furnace or washer, they should have their own breakers. 

For a furnace, it should have a 20 amp breaker. 

For a washer, you should keep a 20 amp breaker. 

You can wire a receptacle in a 20 amp circuit.

The price of the 15 and 20-amp circuit breakers will be the same. 

You can use 12 gauge wires for both 15 and 20 amps. 

You can also use a 14 gauge wire for 15 amps. 

What should be the distance between the sub-panel and the main panel?

The longer the distance is between the sub-panel and the main panel, the more price you have to pay while installing the sub-panel. 

Besides, the sub-panel must easily access the main panel as it will be feeding from the main breaker. 

Also, you must install the panel far above the floor, about 4.5 to 5 feet. 

The distance from the main panel to the basement’s sub-panel should be roughly 10 feet. 

It can be less than 10 feet, like around 4-5 feet, but it should not exceed 10 feet. 

Sometimes, the sub-panel is installed beside the main panel. 

It allows you to cut the power of the sub-panel directly from the main panel.

Can I install the sub-panel?

You need to be an experienced and licensed electrician to have the right to install a sub-panel. 

Besides, you might not do the job as well as the electrician can. 

So, you might make some mistakes, delay the work, and increase your expenses. 

So, it is better to leave this to the electrician. 

However, some states’ NEC does not allow laypersons to do such work. So, without an electrician, you cannot install it. 

Should there be GFCI protection?

GFCI protection is used mostly in damp areas like the kitchen, bathroom, basement, or pool areas.

A basement is a damp place. 

The NEC and other experts suggest using GFCI protections for the basement. 

So, you must have them. 

Whenever they detect any high moisture content, they will trip off. 

GFCIs have a good, responsive feature towards moisture. 

Tripping off will save you from short circuits and other electrical accidents. 

Things will be easier if you get to know the methods of use. 

It will also allow you to know the difference. 

The GFCI outlets have ‘test’ and ‘reset’ buttons. 

To reset the outlet, you need to press only the reset button. 

But you need to reset it manually if it is a breaker. 

Should I bond neutral and ground in the sub-panel?

It would be best not to bond the neutral and ground wires in the sub-panel.

The neutral wire carries the returning current of the main power source. 

On the other hand, the ground wire will not carry any current unless there is a short circuit. 

Bonding the two wires makes the ground wire hot. As a result, the ground wire will give you short circuits. 

However, you can bond the two wires in the main panel. 

Final thoughts

There is no exact size of the sub-panel for the basement. 

The number of appliances running decides the right size.

It can be as low as 60 amps or as high as 200 amps. 

If you have only some lights and outlets, a 60 amp sub-panel will be enough. 

But, if you have many lights, circuits, GFCIs, washers, dryers, furnaces, or other appliances, you need a sub-panel ranging from 100 to 150 amps. 

It is best to have a big one to add more appliances in the future. 

The cost to install a sub-panel range between $400 and $1,750. But, it highly depends on the sub-panel size, labor cost, work challenge, location, wire cost, etc. 


Is 100 amp sub-panel enough?

Most of the houses have a 100 amp electrical service. 

It is the minimum panel suggested by the NEC codes. 

A 100 amp service can provide enough power to a medium-sized house that runs several 120-volt appliances. 

Will upgrading increase the electrical panel’s value?

Upgrading a panel will increase the electrical panel’s value. 

But it is worth it. 

Increasing the panel size will increase the resale value of your house and property and attract more people. 

Can I run a 100 amp sub-panel off a 200 amp main panel?

You can do that without any issue, provided the breaker is not overloaded. 

Where can I place the sub-panel in the basement?

Since the basement is a damp area, deciding the location of the sub-panel is quite concerning. 

Generally, you must place a panel in a dry location. 

Since it is a basement, you have to use GFCI protection.

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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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