💡 Recessed Lighting Layout Calculator
Calculate optimal can light spacing and placement
📊 Quick Reference: Spacing Guide by Ceiling Height
| Ceiling Height | Spacing Between Lights | Distance from Walls | Fixture Size |
|---|---|---|---|
| 8 feet | 4 feet | 2 feet (18-24") | 4" or 5" |
| 9 feet | 4.5 feet | 2.25 feet (24-30") | 5" |
| 10 feet | 5 feet | 2.5 feet (30") | 5" or 6" |
| 12 feet | 6 feet | 3 feet | 6" |
Standard rule: Spacing = Ceiling Height ÷ 2. Task lighting may require closer spacing (subtract 1-2 feet).
"The half-ceiling-height rule works for probably 80% of rooms, but where homeowners go wrong is treating every room the same. I just did a kitchen remodel where the homeowner wanted 8-foot spacing because the ceilings were 16 feet—technically correct, but it looked like an airport hangar. We went with 5-foot spacing instead, and it looked much better. Also, folks forget that task lighting over a kitchen island or reading nook needs to be closer together than general room lighting. I've ripped out more badly spaced recessed lights than I can count. Measure twice, drill once—ceiling drywall repair is expensive and messy."
📐 Understanding Recessed Lighting Layout Principles
Proper recessed lighting layout eliminates dark spots, prevents harsh shadows, and creates uniform illumination across the room.
The Half-Ceiling-Height Rule
This is the foundational spacing rule for recessed lights:
- Spacing between lights: Ceiling height ÷ 2
- Distance from walls: Half the spacing distance
Example: 8-foot ceiling → 4 feet between lights, 2 feet from walls.
Adjustments for Different Lighting Types
Ambient lighting (general): Use standard spacing rule. Goal is even, soft light throughout the room.
Task lighting (kitchen counters, desks): Reduce spacing by 1-2 feet. You need brighter, more focused light for detailed work.
Accent lighting (artwork, displays): Use narrow beam angle fixtures (25°) and adjust distance based on what you're highlighting. Formula: Distance = (Object height × 0.5) to (Object height × 1.0).
Beam Angle Considerations
Most residential recessed lights are 40-60° beam angle (medium to wide). This affects coverage:
- Narrow beam (25°): Accent lighting, artwork. Creates bright spot, less spread.
- Medium beam (40°): Task lighting. Good for counters, reading areas.
- Wide beam (60°+): General ambient lighting. Covers more floor area per fixture.
How to Calculate Manually
Step 1: Calculate spacing distance = Ceiling Height ÷ 2
Example: 8 ft ceiling → 4 ft spacing
Step 2: Calculate wall offset = Spacing ÷ 2
4 ft spacing → 2 ft from walls
Step 3: Determine grid layout
12 ft room width: 2 ft (wall) + 4 ft + 4 ft + 2 ft (wall) = 12 ft → 3 lights across width
12 ft room length: Same calculation → 3 lights along length
Total: 3 × 3 = 9 lights
Step 4: Adjust for room usage
If it's a kitchen with a work island, add 2-3 task lights directly above the island, spaced 3 feet apart instead of 4.
⚠️ Common Mistakes
1. Using 6-inch cans on 8-foot ceilings: They look oversized and create harsh bright spots. Stick with 4-inch or 5-inch for standard ceiling heights. Save 6-inch for 10+ foot ceilings.
2. Placing lights too close to walls (under 18 inches): Creates bright wall wash effect that looks unnatural for general lighting. Unless you're intentionally highlighting walls or artwork, stay 18-24 inches away.
3. Ignoring room shape and furniture layout: A 12×20 foot room isn't the same as a 12×12 square room. Long narrow rooms may need a 2×4 grid instead of evenly spaced. Also, if you know where your dining table will be, center lights over it, not just mathematically centered in the room.
4. Not accounting for beam angle: Narrow beam lights (25°) need to be placed closer together than wide beam (60°). If you use accent lights for general lighting, you'll have dark spots between fixtures.
5. Mixing fixture sizes and types in the same room: Different trim styles, bulb temperatures (warm vs cool), or fixture sizes create an inconsistent look. Buy all fixtures from the same product line to ensure color temperature and beam angle match.
❓ FAQ
What is the spacing rule for recessed lights?
Spacing = Ceiling Height ÷ 2. For 8-foot ceilings, that's 4 feet between lights. Distance from walls should be half that spacing (2 feet).
How many recessed lights for a 12x12 room?
Typically 4 to 6 lights for an 8-foot ceiling. A 2×2 grid (4 lights) works for general ambient lighting. Add more for task lighting or brighter rooms.
How far from walls should recessed lights be?
18 to 24 inches for 8-foot ceilings. The rule is half the spacing distance. Closer than 18" creates bright wall spots; farther than 30" creates dark corners.
What size recessed lights for 8-foot ceilings?
Use 4-inch or 5-inch fixtures. 6-inch cans look too large on standard height ceilings.
Do recessed lights need to be symmetrical?
Not required, but symmetry looks cleaner. If room dimensions don't divide evenly, adjust spacing slightly (±6 inches) to maintain equal distances rather than clustering lights unevenly.