Can Light Spacing Calculator -

Can light spacing — space can lights apart by half the ceiling height. For an 8-foot ceiling, place lights 4 feet apart and 2 feet from the walls. A 12×12 ft room needs 4–6 can lights in a grid. Use the formula: spacing = ceiling height ÷ 2.

Quick answer: Space can lights (recessed lights) 4 feet apart for 8-foot ceilings, and place the first row 2 feet from the wall. The universal rule is: spacing between lights = ceiling height ÷ 2. For a 9-foot ceiling, space lights 4.5 feet apart. For a 10-foot ceiling, 5 feet apart. Never space can lights further apart than the ceiling height.

Calculate your can light spacing — free →

Can light spacing rules — the complete guide

H ÷ 2

Spacing between lights

Divide ceiling height by 2. That’s the maximum spacing between can lights. 8 ft ceiling = 4 ft spacing. 10 ft ceiling = 5 ft spacing.

H ÷ 4

Distance from wall

Divide ceiling height by 4. That’s the offset from each wall. 8 ft ceiling = 2 ft from wall. 10 ft ceiling = 2.5 ft from wall.

1:1

Spacing:height ratio

Spacing should never exceed ceiling height. Exceeding 1:1 creates visible dark patches between fixtures and poor uniformity.

½S

Wall offset = half spacing

The wall offset is always half the between-light spacing. If lights are 4 ft apart, the first light is 2 ft from the wall.

Can light spacing by ceiling height

Ceiling height	Spacing between lights	Distance from wall	Notes
7 ft	3.5 ft (42 inches)	1.75 ft (21 inches)	Low ceiling — use 4-inch fixtures
8 ft	4 ft (48 inches)	2 ft (24 inches)	Standard — most common ceiling height
9 ft	4–4.5 ft	2–2.25 ft	Slightly more flexibility
10 ft	4.5–5 ft	2.25–2.5 ft	Use 6-inch fixtures for wider beam
12 ft	5–6 ft	2.5–3 ft	Consider 8-inch or higher-output fixtures
14 ft+	6–7 ft	3–3.5 ft	High output downlights needed — use calculator

Room-by-room can light spacing guide

Room	Room size	Ceiling	Can lights	Spacing
Small bedroom	10×10 ft	8 ft	4	4 ft grid, 2 ft from walls
Standard bedroom	12×12 ft	8 ft	4–6	4 ft grid, 2 ft from walls
Large bedroom	14×16 ft	9 ft	6–9	4.5 ft grid, 2.25 ft from walls
Small living room	12×14 ft	9 ft	6–8	4.5 ft grid, 2 ft from walls
Large living room	16×20 ft	10 ft	10–14	5 ft grid, 2.5 ft from walls
Kitchen (general)	10×12 ft	9 ft	4–6	4.5 ft grid + task lighting
Hallway (6 ft wide)	Per linear ft	8 ft	1 per 6 ft	Single row down centre
Open plan	20×24 ft	10 ft	16–20	5 ft grid, 2.5 ft from walls

Visual layout — what good can light spacing looks like

12×16 ft living room — 8 can lights at 4 ft spacing (8 ft ceiling)

Why the wall offset matters: If you centre your grid without the 2-foot wall offset, the lights nearest the walls end up 6+ feet from the wall — leaving dark corners that make the room feel smaller. Always start 2 feet from the wall (or ceiling height ÷ 4), not from the room centre.

4-inch vs 6-inch can lights — which spacing?

The fixture diameter doesn’t change the spacing rule — spacing is driven by ceiling height and desired lumen output, not fixture size. But fixture size does affect beam spread:

Can light size	Best ceiling height	Beam coverage	Spacing impact
4-inch	Up to 9 ft	Narrower — good for accents	May need tighter 3–3.5 ft spacing for even coverage
6-inch	8–12 ft	Wider — best for ambient light	Standard 4–5 ft spacing works well
8-inch	12 ft+	Very wide — high ceilings	Can space 5–7 ft apart at height

Switching from 4-inch to 6-inch: If you’re replacing existing 4-inch cans with 6-inch, the spacing rules are the same — but the wider beam means you may be able to skip one fixture in a grid and still achieve even coverage. Use the calculator to check before you cut any new holes.

Common can light spacing mistakes

Spacing from the ceiling centre, not the wall. Many people divide the room evenly from the centre and end up with the outer lights 5–6 feet from the wall. Start from the wall (2 ft in) and work inward.

Spacing too far apart for the ceiling height. Every extra foot of spacing beyond H÷2 creates a visible dark band between fixtures. In a living room, this looks like striped lighting — bright directly under each light, dim in between.

Not accounting for obstructions. HVAC ducts, joists, and beams often force fixture relocation. Always check above the ceiling before committing to a layout — use a stud finder and a small inspection camera if needed.

Single circuit for all lights. Split can lights across at least two circuits so you can dim half the room independently. A living room with 10 can lights works much better as two banks of 5 on separate dimmers.

Frequently asked questions

How far apart should can lights be?

Can lights should be spaced apart by half the ceiling height. For an 8-foot ceiling, space them 4 feet apart. For a 10-foot ceiling, 5 feet apart. Place the first row 2 feet from the wall (half the spacing distance). This is the standard rule used by electricians and lighting designers.

How far from the wall should can lights be?

Place can lights 2 feet from the wall for standard 8-foot ceilings. The formula is ceiling height ÷ 4. For 9-foot ceilings, use 2.25 feet; for 10-foot, 2.5 feet. This prevents dark corners while avoiding harsh glare for anyone seated near the wall.

Can you have too many can lights?

Yes. An over-lit room with can lights on a flat switch feels harsh and clinical. Install dimmers on all circuits — then add a few extra lights if in doubt. A room with 12 dimmable can lights at 30% is far more pleasant than 8 non-dimmable lights at 100%.

How many can lights for a 12×12 room?

A 12×12 ft room with 8-foot ceilings needs 4–6 can lights in a grid pattern. Space them 4 feet apart, starting 2 feet from each wall. A 2×2 grid (4 lights) works for lower brightness needs; a 2×3 grid (6 lights) gives brighter ambient light.

What size can light for an 8-foot ceiling?

Use 4-inch or 6-inch can lights for 8-foot ceilings. Six-inch is more common for general ambient lighting — it produces a wider beam spread. Four-inch is better for accent lighting or rooms where a smaller fixture profile is preferred aesthetically.

Do can lights need to be perfectly symmetrical?

In open rooms, yes — a symmetrical grid looks intentional and professional. In rooms with kitchen islands, furniture zones, or architectural features, offset the grid slightly to centre lights over work areas rather than the geometric room centre. The layout should serve the function of the space, not just the ceiling dimensions.

Get the exact layout for your room

Enter your room length, width, ceiling height, and fixture lumens — the calculator generates a complete grid layout with fixture positions, spacing, and lumen check.

Open the Can Light Spacing Calculator →