How much does it cost to install a subpanel?
Ashburn, VA

How much does it cost to install a subpanel?

Ashburn, VA

How much does it cost to install a subpanel?

$400 – $600cost to install a 50-amp subpanel
$500 – $1,500cost to install a 100-amp subpanel

Get free estimates for your project or view our cost guide below:

$400 – $600 cost to install a 50-amp subpanel

$500 – $1,500 cost to install a 100-amp subpanel

Get free estimates for your project or view our cost guide below:
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Tara Farmer
Written by
Tara Farmer
Edited by
Kristen Cramer
Fact-checked by
Tom Grupa

Average cost to install a subpanel

The average cost to install a subpanel is $400 to $600 for 50 amps or $500 to $1,500 for 100 amps, including labor and materials.

Subpanels prices are $20 to $350 for the part alone.

Cost to install a subpanel
Amperage Unit price range Total cost installed
50 – 60 amps $20 – $90 $400 – $600
100 – 125 amps $30 – $150 $500 – $1,500
150 amps $100 – $200 $600 – $1,800
200 amps $120 – $350 $800 – $2,000

Subpanels are typically smaller than the home's main service panel.

A subpanel's true usable amperage is the amperage of the 240V circuit breaker feeding it power from the main panel.

Get free estimates from electrical panel upgrade near you.

Subpanel installation or replacement cost breakdown

Subpanel installation costs depend on the location, amps, wiring distance from the main electrical panel, and number of circuits.

Subpanel installation cost breakdown
Factor Average cost
Electrical subpanel (50 to 125 amps) $20 – $150
Circuit breakers & supplies $50 – $550
Installation labor $430 – $1,000
Total cost to install $500 – $1,700

Factors affecting the cost include:

  • Size and location – More circuits and a longer wiring distance require more labor and materials.

  • Adding vs. replacing – Replacing a subpanel typically requires less labor as the circuit wiring is already in place. Adding a new subpanel requires wiring each new circuit breaker to a receptacle or appliance.

  • Materials and upgrades – Supplies needed typically include wiring, connectors, fasteners, junction boxes, and possibly GFCI circuits and outlets.

  • Permits & inspections – Installing a subpanel often requires a permit and inspection:

  • Power requirements – Upgrading the main electrical panel may be required provide more power to the subpanel.

Cost to install a subpanel in a garage

Installing a subpanel in a detached garage or structure requires a disconnect switch, more materials, and trenching to run the wire underground from the main structure.

Trenching costs $6.00 to $13.50 per foot to bury electrical wiring.

Electrical subpanel installation in garage
Electrical subpanel installation in garage

Subpanel requirements and upgrade costs

Some subpanel circuits may require GFCI protection for code compliance.

Bathrooms, kitchens, garages, and unfinished basements typically require this safeguard at the circuit breaker or outlet.

  • Installing a GFCI circuit breaker adds $10 to $100+ to the material cost.

  • Installing a GFCI outlet costs $100 to $175 if replacing an existing standard outlet or $150 to $350 when installing a new outlet.

  • Grounding an outlet costs $100 to $300.

Electrician labor cost to replace a subpanel

Electricians charge $40 to $100 per hour to replace a service panel. Most electricians also charge a $75 to $125 service call fee.

Labor costs depend on the size, number of circuits, and whether the current circuits are to code or need rewiring.

New subpanel wiring cost

New subpanel electrical wiring costs $7 to $10 per linear foot. Wiring costs depend on the subpanel's location, number of circuits, wiring distance, and the amount of drywall work involved.

Wiring through walls or underground takes longer and costs more than exterior wiring along a wall. Rewiring a house costs $2 to $4 per square foot.

Cost to move a subpanel

Moving a subpanel costs $1,000 to $3,000+, depending on the distance, number of circuits, and job complexity.

  • Moves involving major rewiring or extensions may require adding junction boxes and connectors, increasing material and labor costs.

  • Moves requiring power company involvement also typically cost more.

Upgrading the main electrical panel

Fuse boxes and 60 to 100-amp main service panels common in older homes are not designed to run most modern appliances.

Experts recommend upgrading to a 200-amp main panel when installing a 100-amp subpanel. The subpanel amps should not exceed 50% of the main panel amps.

Breaker box replacement costs $1,400 to $2,800 when upgrading to 200-amps.

Subpanel installation FAQs

What is a subpanel?

A subpanel is a smaller service panel fed by a 240V breaker on the main panel to extend its circuit capacity.

A subpanel does not increase the home's total power, only its power distribution capabilities, useful for adding circuits to a specific area like a new room or garage.

How long does it take to install a subpanel?

Installing a subpanel takes 4 to 8 hours on average, depending on the number of circuits, distance between the panels, and amount of drywall repair needed.

Subpanels installed close to the main service panel take less time to install than those installed far away from it or needing extensive rewiring.

When should I upgrade my subpanel?

Upgrade your subpanel if it is older than 25 years or if your home needs more circuits than the current subpanel supplies.

Replace Federal Pacific and Zinsco subpanels as soon as possible due to a known fire risk in these brands. Experts also recommend upgrading outdated Challenger and PushMatic/Bulldog panels.

Adding heavy power demand may require upgrading the main service panel instead of adding a subpanel. Signs your main panel is overloaded include:

  • Lights flickering or dimming

  • Buzzing sounds

  • Outlet burn marks

  • Panel feels hot

  • Plastic burning smell

  • Visible smoke

  • Frequent circuit breaker tripping

Do subpanels need a main breaker?

Subpanels do not need a main breaker when installed in the same building as the main service panel. The main breaker in the main service panel acts as the subpanel's disconnect breaker.

A subpanel installed in a different structure requires a main breaker to allow for quick disconnection if needed.

Can you add a subpanel to a subpanel?

You can add a subpanel to a subpanel in most cases, provided the added demand does not exceed the main service panel's limits.

Calculate the new subpanel's demand using the National Electrical Code (NEC) load calculation guidelines or consult an electrician to confirm the new subpanel is feasible and compliant.

Can I install a subpanel myself?

You can install a subpanel yourself if you are confident working with electrical wiring and know the local building codes and national safety requirements, but hiring an electrician is best.

A licensed electrician has the proper training, tools, and equipment to ensure the installation is safe and up to code.

How far can a subpanel be from the main panel?

A subpanel can be any distance from the main panel if connected with a correctly sized cable.

Subpanels far away from the main panel require thicker cable to account for voltage drops due to the increased distance. Subpanels installed in a different building from the main panel require a disconnect.

  • A subpanel adding space to the main panel is often installed next to the main panel.

  • A subpanel serving a designated home area may be installed in that area.

How many amps can a subpanel be?

There is no limit on the subpanel’s amp size. However, the subpanel is limited by the amp size of the main breaker panel and the circuit breaker that feeds it.

A 200-amp subpanel wired to a 60-amp breaker will only provide 60 amps.

  • Some experts recommend the subpanel amps not exceed 50% of the main panel amps.

  • Confirm the maximum subpanel size allowed by your utility company as some companies limit the size.

Getting estimates from subpanel installers

Before getting an electrical panel upgrade, be sure to:

  • Get at least three estimates to compare.

  • Browse their reviews on HomeGuide and Google.

  • Hire a licensed, bonded, and insured electrician that has been in business more than 5 years.

  • Avoid going with the lowest quote as quality may suffer.

  • Get a detailed contract and warranty in writing before the project begins.

  • Never pay in full before the work is complete. Work out a payment plan instead.

Questions to ask

  • How long have you been in business?

  • Are you licensed, bonded, and insured?

  • What experience do you have installing subpanels?

  • What size subpanel do you recommend?

  • Is my main service panel powerful enough to support this subpanel?

  • Can you provide local references with contact information?

  • Do you handle the permits and inspection process?

  • Are all permit and inspection fees included in the estimate?

  • What additional costs might come up during installation?

  • How long will the installation take?

  • Do you offer a warranty? If yes, what does it cover?