Most garages were wired for parking: one bulb in the middle of the ceiling, one outlet by the door, done. The moment it becomes a workshop — compressor, welder, dust collector, heater — that single 15-amp circuit becomes a fire-adjacent annoyance, and that one bulb turns out to be useless over a workbench. This guide covers both halves of the job: how many circuits a working garage actually needs, and how to light it so you can see what you are doing.
Start With the Loads
| Equipment | Running Watts | Circuit Needed |
|---|---|---|
| LED shop lights (whole garage) | 100–200W | Share a lighting circuit |
| 1/2" corded drill, saws | 600–1,500W | Shared 20A receptacle circuit |
| Air compressor (2 HP) | 1,500–2,400W | Dedicated 20A, or 240V |
| Table saw / cabinet saw | 1,800–3,000W | Dedicated 20A, or 240V |
| Welder (hobby, 140A) | 3,000–4,500W peaks | 240V / 30–50A |
| Electric heater (5 kW) | 5,000W | Dedicated 240V / 30A |
| Mini-split (12–18k BTU) | 800–1,800W | Dedicated 15–20A, 220V usually |
The pattern should be obvious: everything with a motor or a heating element wants its own circuit. Hand tools are the only things that share happily.
The Standard Workshop Circuit Plan
- Two 20-amp receptacle circuits around the walls (12-gauge wire). Code requires 20A circuits in garages anyway; two means the compressor and the miter saw are never fighting. Put outlets every 6 to 8 feet so you never need an extension cord.
- One lighting circuit for all fixtures, so a tripped tool outlet never leaves you in the dark mid-cut.
- One dedicated 20A circuit at the bench location — this is where the big bench tools and battery chargers live.
- 240V provision even if you do not need it yet: run a 10-gauge, 30–50A circuit to where a welder or compressor would sit. It costs little during a rewire and everything later, and it is also the circuit a future lift motor wants — see the ceiling height and lift clearance guide.
GFCI, Code, and Honest Disclaimers
- All 125V, 15–20A receptacles in garages must be GFCI-protected under US code (NEC). GFCI receptacles or a GFCI breaker both satisfy this.
- Outlets in unfinished walls need boxes; nothing runs through fire blocks unprotected.
- A subpanel in the garage (typically a 60–100A feeder from the house) is the clean way to get multiple 240V circuits without filling the main panel.
- We are planners, not electricians: local codes vary, permits exist, and panel work is genuinely dangerous. Use this to plan the layout and the outlet counts, and have the final work inspected.
Plan Outlets With the Layout
Place your bench, compressor, and lift in the planner first — then mark where each outlet and 240V drop needs to land on the wall behind them.
Open Free Garage PlannerOutlet Placement Details That Matter
Outlets sit roughly 44 to 48 inches off the floor in a workshop — above bench height, below shelving, and out of the snow-splash zone near doors. At the workbench, add a power strip on the pegboard rather than wall outlets, because bench tools move constantly. And leave one outlet near the garage door opener (most openers are hardwired or need a receptacle within reach) and one at the freezer or fridge location, if either lives in the garage — those belong on their own circuit so a tripped saw never thaws your food. For the heating side of the electrical equation, see our garage heating comparison.
Panel Capacity: Do You Have Room for Any of This?
Before planning circuits, open the panel and count. You need to know three things:
- Free breaker slots. Two 20-amp receptacle circuits, a dedicated bench circuit, a lighting circuit, and a 240V run means five slots at minimum. Most 100-amp panels are already full once a house has a dryer, range, air conditioner, and general lighting.
- Service size. A 100A service can usually carry a modest workshop load. Once you add a welder, a 5 kW heater, a big compressor, and a future EV charger, the honest answer is often a sub-panel or a 200A service upgrade.
- What "dedicated" costs you. Every dedicated circuit consumes two slots when it is 240V, and tandem breakers are not permitted on every panel bus.
A garage sub-panel is frequently the cheapest path forward: one 240V feeder from the house panel to a small panel in the garage, then every workshop circuit lands where it is convenient to reset. Plan for it early, and reserve the wall space — a panel needs clear working space in front of it that no shelf, cabinet, or parked car may occupy.
Wire Size, Voltage Drop, and Long Runs
- 20A circuits: 12-gauge copper, no exception. Fourteen-gauge wire on a 20A breaker is how garages get warm in the wrong way.
- 240V at 30A (small heater, hobby welder): 10-gauge. 240V at 50A (larger welder, EV charging, big compressor): 6-gauge copper for typical runs.
- Voltage drop: a welder in the far corner of a long garage, fed from a panel at the opposite end of the house, can see a noticeable dip during inrush. Runs beyond roughly 100 feet often call for one size up. A sub-panel in the garage solves this and most future problems at once.
- Receptacle spacing: the goal is that no tool ever needs an extension cord. Outlets every 6 to 8 feet along the walls, plus a cluster at each bench, achieves that in most garages.
Switching: Plan It Before the Drywall
Put every light in the garage on its own circuit, so a tripped tool outlet never plunges the room into darkness mid-cut. Then think about switches: a garage with two service doors wants 3-way switching at each, plus a switch reachable from the car door, because a light you cannot turn on before stepping inside is a light you will leave off. If you plan overhead storage or a lift, coordinate fixture positions with the ceiling plan — a fixture sitting in the path of a ceiling rack is a fixture that ends up in the trash. The storage clearance guide covers keeping the space around that hardware usable.
Lighting: Forget Watts, Start From Lumens
Watts measure energy consumption, not brightness. Since LEDs use a fraction of the power of the bulbs they replaced, comparing watts tells you nothing useful about how much light actually lands on a workbench. Lumens are the measure of visible light output, and every lighting calculation in a garage starts there.
| Zone | Target | Notes |
|---|---|---|
| General area lighting | ~50 lumens / sq ft | Bright base layer for parking and walking |
| Workbench task lighting | ~300 lumens / sq ft | Measured on the bench surface, not the floor |
| Engine bay / under vehicle | Portable or strip | Overhead fixtures cannot reach here at all |
The worked example that matters: a standard 24' x 24' two-car garage is 576 square feet, so 576 × 50 = 28,800 lumens for even general illumination. A typical 4-foot LED shop light produces 4,000 to 5,000 lumens, which puts the shopping list at six or seven linked fixtures. Task lighting over the bench is added on top of that number — the general layer is never expected to cover detail work.
Three Kinds of Light a Workshop Needs
- Area lighting. Ceiling-mounted fixtures. Long LED shop lights — the ones shaped like the fluorescent tubes they replaced — are the best value: wide, even distribution for the money. High-bay UFO fixtures only earn their price once the ceiling is above roughly 15 feet.
- Task lighting. A dedicated LED strip directly over the bench, positioned so it does not throw the shadow of your own head onto the work. This is the highest-value single fixture in any shop.
- Portable lighting. Battery work lights, under-hood lights, and magnetic puck lights for the places overhead light physically cannot reach.
Color Temperature: 4000K to 5000K
- 2700K–3000K (warm white): Cozy, and wrong for a garage — it flattens the contrast you need most.
- 4000K (cool white): A reasonable compromise: bright without feeling clinical.
- 5000K (daylight): The sweet spot for detail work. Best contrast and colour rendering, which is what lets you tell one wire colour from another or read a stamped part number.
- 6000K and above: Harsh enough to strain your eyes across a long session.
Placement: Runs, Not One Bulb in the Middle
Clustering fixtures in the centre of the ceiling — usually right where the door opener hangs — is the classic mistake. Park a car under it and the light lands on the roof, leaving deep shadow exactly where anyone works. Run fixtures in parallel along the sides of the parking bays instead: in a two-car garage, one run over the left bay, one down the centre between the cars, and one over the right bay. That puts light on the flanks of the vehicles and on the walking paths.
Spacing follows ceiling height: keep parallel runs roughly 4 to 6 feet apart under an 8- to 10-foot ceiling, and space fixtures about the same distance along each run so the pools overlap instead of sitting in islands. Higher ceilings need wider spacing and more output per fixture. Check the ceiling height guide before committing to high-bay fixtures, because the door track and opener claim a surprising slice of that space.
Zone the switching: general lighting on one switch, bench task lights on another. Everything at full brightness at once is what makes a shop feel harsh, and lighting only the bay you are using is what makes evenings in it pleasant.
Place Outlets and Fixtures on the Plan
Drag benches, compressors, and lifts onto the floor plan first, then mark where each outlet, 240V drop, and fixture run needs to land — before any of it goes behind drywall.
Open Free Garage PlannerOne last habit worth building: label the panel. Every circuit in a workshop ends up feeding something surprising six months later, and a handwritten index on the inside of the door costs nothing.
Frequently Asked Questions
How many electrical circuits does a garage workshop need?
Plan on five at minimum: two 20-amp receptacle circuits around the walls, one lighting circuit, one dedicated 20-amp circuit at the bench, and one 240V run for a welder, compressor, or future EV charger. A 100-amp service can usually carry a modest workshop load, but a welder plus a 5 kW heater plus a large compressor usually means a sub-panel or a 200-amp service upgrade.
Do garage outlets need to be GFCI protected?
Yes. Under the National Electrical Code, all 125-volt, 15- and 20-amp receptacles in a garage must be GFCI protected. Either GFCI receptacles or a GFCI breaker satisfies the requirement, and a GFCI breaker is usually cheaper when several outlets share one circuit.
How many lumens do I need to light a garage?
Around 50 lumens per square foot for general area lighting, so a 24' x 24' two-car garage (576 square feet) needs roughly 28,800 lumens. That works out to six or seven 4-foot LED shop lights at 4,000 to 5,000 lumens each. Task lighting over a workbench is added on top, at roughly 300 lumens per square foot of bench surface.
What color temperature should garage lighting be?
4000K to 5000K. 5000K daylight gives the best contrast and colour rendering for seeing wire colours and reading labels, and 4000K is a slightly softer compromise. Warm 2700K to 3000K light is too yellow for detail work, and above 6000K becomes harsh enough to strain your eyes over a long session.
Can garage lights and outlets share a circuit?
Keep them separate. If the lights share a circuit with tool outlets, tripping a breaker mid-cut plunges the room into darkness with a blade still spinning. A dedicated lighting circuit costs one breaker slot and one run of cable.