Recessed Lighting Calculator
Calculate recessed lighting spacing and layout. Determine optimal fixture count and spacing for room.
Formula
Fixtures = ⌈(Length ÷ Spacing) × (Width ÷ Spacing)⌉
- Spacing distance ≈ ceiling height ÷ 5 (rule of thumb)
- Lumens needed ≈ 3 per sq ft (recommended for general room lighting)
- 60W LED equivalent ≈ 800 lumens
- Adjust based on task (kitchen may need 5 lumens/sq ft)
Example
Inputs
- Room Length (ft): 20
- Room Width (ft): 15
- Ceiling Height (ft): 9
20×15 ft room, 9 ft ceiling: 12 fixtures in 4×3 grid, 1.8 ft spacing
Frequently asked questions
What spacing should I use?
General rule: 1.5× ceiling height for general lighting, 1× ceiling height for task lighting.
How many lumens do I need?
3-5 lumens per sq ft for general rooms, 5-10 for kitchens/bathrooms, 1-2 for bedrooms.