Garage Electrical Guide

Circuit requirements, outlet placement, EV charger prep, and subpanel considerations

Why Proper Garage Electrical Planning Matters

A well-planned garage electrical system provides adequate power for current needs while accommodating future requirements. Garages are evolving from simple car storage to workshops, hobby spaces, and EV charging stations, requiring thoughtful electrical design.

Improper garage wiring can lead to nuisance breaker trips, insufficient power for tools and equipment, inability to add EV charging, and safety hazards. Planning circuits properly from the start saves money and frustration compared to retrofitting later.

Key Planning Principle: Always install more circuits and outlets than you think you'll need. Adding circuits during construction is inexpensive; retrofitting later is costly and disruptive. Consider future needs like EV charging, woodworking equipment, and additional lighting.

Minimum Circuit Requirements

Circuit Type	Breaker Size	Wire Size	Code Requirement/Use
Lighting	15A or 20A	14 AWG (15A) or 12 AWG (20A)	Required by NEC. Can be shared with interior lighting or dedicated.
General Receptacles (GFCI)	20A	12 AWG	Required by NEC. All garage receptacles must be GFCI protected.
Garage Door Opener	15A or 20A	14 AWG or 12 AWG	Can be on lighting circuit or dedicated. Dedicated is preferred.
Workshop/Tool Circuit	20A	12 AWG	Recommended for power tools. Multiple circuits for heavy use.
240V Outlet (Welder/Compressor)	30A or 50A	10 AWG (30A) or 6 AWG (50A)	Optional. For heavy equipment like welders, air compressors, table saws.
EV Charger (Level 2)	40A to 60A	8 AWG (40A) or 6 AWG (50A)	Increasingly common. Plan conduit and breaker space even if not installing now.

NEC Requirements: The National Electrical Code (NEC Article 210.52(G)) requires at least one 120V, 20A receptacle in attached garages. All 120V receptacles in garages must be GFCI protected per NEC 210.8(A)(2).

Outlet and Lighting Placement

Receptacle (Outlet) Placement Guidelines

Location	Recommendation	Notes
Workbench Area	One outlet every 4 feet	20A circuit, GFCI protected. Mount at workbench height (42"-48").
General Wall Outlets	One on each wall minimum	Standard 15"-18" above floor. More is better for flexibility.
Garage Door Opener	Ceiling outlet centered on door	Can be unswitched or on separate switch. 5-10 ft from door track.
EV Charging Location	240V, 50A outlet or hardwired	4-5 feet high on wall where car will park. Consider both sides if two cars.
Exterior (near overhead door)	Weather-resistant outlet	GFCI protected, in-use cover. Useful for lawn equipment, car washing.
Corner/Hard-to-Reach Areas	Floor outlets (optional)	Useful for center-of-garage tool use. Must be GFCI and proper rated box.

Lighting Placement Guidelines

General lighting: LED shop lights or flush mounts spaced 8-10 feet apart
Minimum requirement: One wall-switched light per code (NEC 210.70(A)(2))
Task lighting: Additional fixtures over workbench, tool areas, and entry doors
Motion sensor: Consider motion-activated lighting for convenience and energy savings
Light level target: 50-75 lumens per square foot for general use; 75-100 for workshop areas
Exterior lighting: Light near man door and overhead door for security

Recommended Outlet Count by Garage Size

1-car garage (12×20 ft):6-8 outlets minimum

2-car garage (20×20 ft):10-12 outlets minimum

3-car garage (30×20 ft):14-16 outlets minimum

These are recommendations; code requires only one 20A GFCI receptacle. More outlets provide better functionality and future-proofing.

GFCI Requirements for Garages

What Requires GFCI Protection?

ALL 120V receptacles in garages: Required by NEC 210.8(A)(2)
Includes: Wall outlets, workbench outlets, and accessible garage door opener receptacles
Exceptions: Receptacles that are not readily accessible (ceiling-mounted door opener) and dedicated outlets for garage door openers MAY be exempt depending on local code interpretation
240V outlets: Generally not required to be GFCI, but check local codes (some require GFCI for 240V in garages)

GFCI Protection Methods

GFCI Breaker

Pros:

Protects entire circuit at panel
No need for GFCI outlets
Cleaner look (standard outlets throughout)
Centralized testing location

Cons:

More expensive ($40-60 vs $15 per outlet)
Harder to reset (must go to panel)
One trip affects entire circuit

GFCI Outlet (First in Line)

Pros:

Less expensive initially
Easy to reset at outlet
Can protect downstream outlets
Standard breaker at panel

Cons:

Takes up more box space
Visible test/reset buttons
Must wire LINE/LOAD correctly
Can be harder to troubleshoot

Best Practice: For garages with multiple circuits, use GFCI breakers for convenience and reliability. For single-circuit garages, a GFCI outlet as the first receptacle protecting downstream outlets is cost-effective.

240V Outlets for Tools and Equipment

Common 240V Garage Equipment

Equipment	Typical Amperage	Recommended Outlet	Wire Size
Air Compressor (5+ HP)	20-30A	NEMA 6-30R or 6-50R	10 AWG (30A) or 6 AWG (50A)
Welder (MIG/TIG)	30-50A	NEMA 6-50R (most common)	6 AWG (50A)
Table Saw (Cabinet Style)	20-30A	NEMA 6-20R or 6-30R	12 AWG (20A) or 10 AWG (30A)
Dust Collection System	20-30A	NEMA 6-20R or 6-30R	12 AWG (20A) or 10 AWG (30A)
Electric Heater	20-30A (per unit)	Hardwired or NEMA 6-30R	12 AWG (20A) or 10 AWG (30A)

240V Outlet Types (NEMA Configurations)

NEMA 6-20R (20A, 240V): T-slot receptacle, common for smaller tools
NEMA 6-30R (30A, 240V): Three-prong (no neutral), common for welders and compressors
NEMA 6-50R (50A, 240V): Three-prong (no neutral), heavy-duty equipment and some EV chargers
NEMA 14-30R (30A, 240V + Neutral): Four-prong with neutral, dryers (not common in garage)
NEMA 14-50R (50A, 240V + Neutral): Four-prong with neutral, RV outlets and many Level 2 EV chargers

Planning Tip: If you're unsure about future 240V needs, install conduit and a dedicated breaker space during construction. Running 6 AWG wire through walls later is difficult and expensive. A capped-off NEMA 6-50R outlet gives maximum flexibility.

EV Charger Circuit Requirements

Level 1 vs Level 2 Charging

Charging Level	Voltage	Amperage	Charging Speed	Circuit Requirement
Level 1 (Standard)	120V	12-16A	3-5 miles of range per hour	Standard 120V outlet, 20A circuit recommended
Level 2 (Fast)	240V	16-80A (typically 32-40A)	15-40 miles of range per hour	Dedicated 240V circuit, 40-60A breaker

Recommended Level 2 EV Charger Circuits

Charger Rating	Circuit Breaker	Wire Size (Copper)	Use Case
16A Charger	20A (2-pole)	12 AWG	Basic Level 2, budget-friendly
32A Charger	40A (2-pole)	8 AWG	Most common, good balance of speed and cost
40A Charger	50A (2-pole)	6 AWG	Faster charging, future-proof
48A Charger	60A (2-pole)	6 AWG	High-performance EVs, maximum home charging speed

Installation Considerations

Outlet vs Hardwired: NEMA 14-50 outlet provides flexibility; hardwired is more permanent and allows full charger amperage
Location: Mount charger 4-5 feet high on wall where car parks, ensure cable reaches charge port (consider passenger vs driver side)
Future-proofing: Install 50A or 60A circuit even if buying 32A charger; easy to upgrade charger later
Multiple vehicles: Consider two separate circuits or a load-sharing charger system
Panel capacity: Large EV circuits may require service upgrade (see Subpanel section below)
Conduit: Run conduit between panel and charger location for easy wire upgrades

80% Rule: Continuous loads (like EV chargers) must not exceed 80% of circuit capacity. A 40A breaker can safely supply a 32A charger. Always size breaker 125% of charger rating.

Subpanel Installation Considerations

When to Install a Garage Subpanel

Distance from main panel: Garage is far from main panel (over 50 feet or separate building)
Multiple circuits needed: Planning 5+ garage circuits (lighting, outlets, 240V, EV charger)
No breaker space: Main panel is full and cannot accommodate additional circuits
Workshop/hobby space: Heavy tool use requiring multiple dedicated 240V circuits
Detached garage: Separate structure requires its own panel per code in most jurisdictions

Subpanel Sizing Guide

Subpanel Size	Feeder Breaker	Feeder Wire Size	Best For
60A Subpanel	60A (2-pole)	6 AWG copper or 4 AWG aluminum	Basic garage: lighting, outlets, small 240V circuit
100A Subpanel	100A (2-pole)	2 AWG copper or 1/0 AWG aluminum	Standard garage with EV charger or multiple 240V circuits
125A Subpanel	125A (2-pole)	1 AWG copper or 2/0 AWG aluminum	Heavy workshop use, multiple high-draw circuits
200A Subpanel	200A (2-pole)	2/0 AWG copper or 4/0 AWG aluminum	Detached garage with workshop, multiple EVs, HVAC

Subpanel Installation Requirements

Four-wire feeder: Two hots, neutral, and ground (separate ground and neutral buses in subpanel)
Grounding: Subpanel must have separate grounding electrode system if detached structure
Feeder protection: Breaker in main panel sized to feeder wire capacity
Conduit: PVC or EMT conduit required for feeder run if not in finished space
Main breaker: Subpanel may have main breaker (load center) or be main lug only (depends on application)
Disconnect requirement: Detached garages require exterior disconnect per NEC 225.31

Hire a Licensed Electrician: Subpanel installation requires expertise in load calculations, wire sizing, grounding, and code compliance. This is not a DIY project for most homeowners. Always hire a licensed electrician for subpanel work.

Garage Door Opener Wiring

Power Requirements

Standard voltage: 120V AC, 15A or 20A circuit
Typical draw: 5-7 amps during operation, less than 1 amp standby
Dedicated circuit: Recommended but not required; can share with lighting circuit
GFCI requirement: Check local codes; some require GFCI, others exempt "not readily accessible" receptacles

Outlet Location and Installation

Ceiling-mounted receptacle: Most common installation, mounted near opener unit
Distance from door track: 5-10 feet away from door track, centered on door
Height: Outlet should be within 6 feet of opener unit for cord connection
Accessibility: Must be accessible for unplugging (unplug for service/vacation)
Switch control (optional): Can add wall switch to control power to opener circuit

Low-Voltage Wiring (Door Controls and Safety Sensors)

Wall button wire: 22/2 or 24/2 low-voltage wire from opener to wall button
Safety sensor wire: 22/2 wire from opener to safety sensors (photo eyes) at door bottom
Run before drywall: Fish wires through walls during construction or before finishing
Staple carefully: Don't over-compress low-voltage wire with staples (can damage insulation)
Avoid interference: Keep low-voltage wires 12"+ away from high-voltage wires when running parallel

Typical Garage Door Opener Installation

Step 1: Install ceiling junction box within 6 feet of where opener will mount

Step 2: Run 14/2 or 12/2 NM cable from circuit breaker to junction box

Step 3: Install outlet receptacle in ceiling box (can be unswitched or switched)

Step 4: Run 22/2 low-voltage wire from ceiling area to wall button location (typically 4-5 ft high near entry door)

Step 5: Run 22/2 low-voltage wire from ceiling to both safety sensor locations (6" above floor on each side of door)

Step 6: After opener installation, plug opener into ceiling receptacle and connect low-voltage wires per manufacturer instructions

Step-by-Step Electrical Planning Process

Assess Current and Future Needs

List all current and anticipated electrical needs: lighting, outlets, tools, EV charging, HVAC, etc. Consider 5-10 year future needs. Overestimate outlet counts and circuit capacity.

Calculate Load Requirements

Add up amperage requirements for all planned circuits. Check if main panel has capacity or if subpanel is needed. Consult electrician for load calculation if adding large loads.

Create Electrical Layout Drawing

Draw garage floor plan with outlet locations, light fixture locations, switch locations, and 240V outlet locations. Mark workbench areas, EV parking spots, and equipment locations.

Plan Circuit Distribution

Group outlets into logical circuits (max 10-12 outlets per 20A circuit). Separate lighting and outlets. Dedicate circuits for large loads. Ensure GFCI protection for all 120V garage circuits.

Install Conduit and Boxes During Framing

Install electrical boxes, conduit runs (if needed), and junction boxes during framing stage. This is the easiest time to add extra circuits and future-proofing conduit. Mark circuits clearly.

Run Wire and Make Connections

Pull wire through conduit or between studs. Use correct wire gauge for each circuit. Secure with staples within 12" of boxes. Leave 6-8" of wire at each box for connections. Label all circuits.

Schedule Inspection Before Covering Walls

Call for electrical rough-in inspection before insulating or drywalling. Inspector will verify wire sizing, box placement, GFCI protection, and code compliance. Make any required corrections.

Install Devices and Schedule Final Inspection

After drywall/finishing, install outlets, switches, and fixtures. Install breakers in panel. Schedule final electrical inspection. Inspector will test GFCI outlets and verify proper installation.

Safety and Code Considerations

Electrical Shock Hazard: Always turn off power at the breaker before working on electrical circuits. Use a voltage tester to verify power is off. Never work on live circuits. Death or serious injury can occur.

GFCI Protection Required: All 120V receptacles in garages must be GFCI protected per NEC 210.8(A)(2). Non-GFCI outlets in garages are a code violation and safety hazard. Retrofitting existing garages is strongly recommended.

Permit and Inspection Required: Most jurisdictions require electrical permits and inspections for new circuits, subpanels, and service upgrades. Unpermitted work may void insurance, make home unsaleable, and is illegal in most areas.

Wire Sizing Critical: Undersized wire causes overheating, fire risk, and voltage drop. Always follow NEC wire sizing tables. Use 12 AWG minimum for 20A circuits, 10 AWG for 30A, 6 AWG for 50A. Never exceed wire ampacity.

Note: Electrical codes vary by location and are updated regularly. This guide is for informational purposes only. Always consult a licensed electrician for complex work, and verify all requirements with your local building department. DIY electrical work may be restricted or prohibited in your area.

Quick Reference Summary

Minimum Code Requirements

At least one 20A receptacle (GFCI protected)
At least one wall-switched light
All 120V outlets GFCI protected
Garage door opener outlet (accessible for unplugging)

Recommended Best Practices

Multiple 20A circuits for outlets and tools
Dedicated circuit for garage door opener
50A 240V circuit for future EV charging
One outlet every 6-8 feet on walls
Workbench outlets every 4 feet
Consider subpanel if planning 5+ circuits

Disclaimer: This guide provides general information about garage electrical planning. Electrical codes, local requirements, and project-specific factors vary significantly. Always consult with a licensed electrician for design, installation, and inspection. Improper electrical work is dangerous and potentially deadly. When in doubt, hire a professional.