Recessed Lighting Calculator
Design a balanced grid of can lights or downlights. Estimate how many fixtures you need, how to space them, and how bright they will feel.
Living rooms, hallways, bedrooms
Typical 6" LED can = 650–900 lumens.
Use current dimmer setting to see effective brightness.
Recommended Layout
Total fixtures
6
3 rows × 2 columns
Spacing Along Length
6 ft
≈ 1.8 m
Spacing Along Width
7 ft
≈ 2.1 m
Brightness Check
Target
3,780 lumens needed (15 fc)
Room area: 252 sq ft
Supplied
5,100 lumens delivered
34.9% brighter than minimum
How to Use This Calculator
Measure the room
Enter length, width, and ceiling height in feet. Accurate measurements ensure even spacing.
Pick the lighting goal
Choose ambient, task, or accent to set the right footcandle target and spacing guidelines.
Verify brightness
Adjust lumens per fixture or dimming level to fine-tune the overall light output for comfort.
Formula
Required Lumens = Room Area (sq ft) × Target Footcandles
Fixtures Needed = Required Lumens ÷ Lumens per Fixture
Recommended Spacing ≈ Ceiling Height × Spacing Multiplier
Example: 18 × 14 ft living room (252 sq ft) × 15 fc → 3,780 lumens required. With 850 lm trims you need about 5 lights.
Spacing: 9 ft ceiling × 1.5 multiplier ≈ 13.5 ft spacing. A 3 × 2 grid refined down to ~6 ft spacing keeps brightness uniform.
Design Tips
Thoughtful recessed lighting highlights architecture without glare. Use this layout as a baseline, then fine-tune around furniture, artwork, and natural light sources.
Placement guidelines
- Keep fixtures at least 18 inches from walls to avoid scallops.
- Center a row over major seating or workspace zones.
- Pair task lighting over counters with pendants or under-cabinet lights.
- Use adjustable gimbals for accenting art or fireplace textures.
Layer the light
- Add dimmers to create multiple moods from one layout.
- Combine with sconces and floor lamps to soften shadows.
- Choose warm (2700K) for cozy spaces or neutral (3000–3500K) for kitchens.
Frequently Asked Questions
How far should recessed lights be from the wall?
Keep trims 1.5–3 ft off the wall to avoid harsh scallops and let light wash evenly down the surface.
Do I need fewer lights with higher lumens?
Higher lumen trims can reduce the fixture count, but spacing still matters. Spread them out to prevent bright spots.
What about sloped ceilings?
Use adjustable gimbal trims aimed perpendicular to the floor. Measure spacing along the slope for even coverage.
Should I mix 4" and 6" cans?
Mixing sizes can add visual interest. Use smaller trims near focal points and larger ones for ambient fill.