Subpanel Installation Cost: Garage, Shop & Addition Panels
Installing a subpanel typically costs $700 – $2,000 for a 60 to 100 amp panel, including the panel, the feeder cable, breakers, and labor. The big variable is distance: a subpanel a few feet from the main panel is cheap, while a detached garage or shop that needs a trenched feeder runs $1,500 – $4,000 or more. Here is the breakdown.
Talk through this project
Describe the job, get matched with a local licensed pro on the line.
(612) 353-8317New installs, replacements & repairs · No obligation
| Location | Installed range | Notes |
|---|---|---|
| Same room as main panel | $500 – $1,000 | Short feeder, easy access |
| Elsewhere in the house | $700 – $1,800 | Feeder fished through walls |
| Attached garage | $800 – $2,000 | Short feeder run, surface conduit |
| Detached garage or shop | $1,500 – $4,000 | Trenched or overhead feeder |
| Home addition | $1,000 – $2,500 | Feeder plus addition circuits |
| Line item | Typical range | Notes |
|---|---|---|
| Subpanel & breakers | $100 – $400 | 60A to 100A load center |
| Feeder cable | $2 – $8 / ft | Heavier wire for higher amps |
| Trenching (detached) | $5 – $15 / ft | Hand vs machine, soil, depth |
| Conduit & fittings | $50 – $300 | Required for buried or exposed runs |
| Electrician labor | $400 – $1,500 | Scales with feeder distance |
| Permit & inspection | $75 – $300 | Required in most jurisdictions |
Want a real number instead of a range?
Calls are answered around the clock and routed to a licensed electrical pro serving your area.
Call & describe the job
Tell us what you need: a new install, an upgrade, or something that stopped working.
Get matched on the line
You are connected with a local licensed electrical pro who serves your area.
Compare your numbers
Use the ranges on this page to sanity-check the quote before you commit.
What a subpanel does and when you need one
A subpanel is a secondary breaker panel fed from your main panel. It does not add capacity to your service. It distributes the capacity you already have to a part of the house or property where running individual circuits back to the main panel would be impractical, and understanding how a subpanel differs from the main panel clears up most of the confusion. Think of it as a branch office: power flows to it through one feeder, then splits into local circuits.
Subpanels make sense in four common situations: a detached garage or shop that needs several circuits, a home addition where running every circuit back to the main panel is a long haul, a main panel that has run out of breaker slots, and a workshop with heavy 240-volt tool loads. A subpanel is also the usual way to handle the cost of running power to a shed or outbuilding. In all of these, one feeder to a subpanel is cleaner and often cheaper than many long home-run circuits.
Why distance is the main cost driver
The panel and breakers are a small, predictable cost. What moves a subpanel quote from $700 to $4,000 is the feeder: the cable that carries power from the main panel to the subpanel. A subpanel mounted next to the main panel needs a few feet of cable and an hour of labor. A subpanel in a detached shop 80 feet across the yard needs a long feeder run, and how it gets there matters.
- ·Overhead feeder: a cable strung between the house and an outbuilding, cheaper than trenching but constrained by clearance rules.
- ·Underground feeder: buried in conduit, which means a trench. Trenching runs $5 – $15 per foot depending on soil, depth, and whether it is hand-dug or machine-dug.
- ·Wire size: a longer run needs larger conductors to limit voltage drop, which raises the cable cost per foot.
- ·Obstacles: crossing a driveway, a patio, or tree roots adds real labor and sometimes concrete cutting.
Sizing the subpanel and its feeder
Subpanels are commonly 60 or 100 amps. A 60-amp subpanel handles a modest garage or addition: lights, outlets, and maybe one 240-volt circuit. A 100-amp subpanel suits a serious workshop with a welder, a dust collector, an air compressor, or an EV charger. The feeder cable and the breaker protecting it in the main panel have to match the subpanel rating.
Two rules trip up DIY subpanel jobs and matter for the quote. First, a subpanel must keep its neutrals and grounds separate (isolated neutral bar), unlike the main panel where they bond. Second, a detached structure needs its own grounding electrode (ground rods). Both are code requirements an inspector checks, and skipping them is a common reason a job fails inspection.
Does the main panel have room to feed it?
Before adding a subpanel, the electrician confirms two things about the main panel: that it has an open double-pole slot for the feeder breaker, and that the existing service has enough spare capacity to support the new loads. A subpanel does not create power out of nothing. If you bolt a 100-amp subpanel onto a maxed-out 100-amp service, you can overload the main.
If the main panel is full or the service is already near capacity, the conversation shifts to a 200A service upgrade first. That is a different and larger project, but it is better to learn that during planning than after the subpanel is installed and the main breaker starts tripping. A quick load calculation during the quote prevents that surprise.
Ready to get it handled?
One call, no obligation. Describe the job and compare the quote against the ranges above.