Recessed Lighting Calculator
Calculate how many recessed lights you need and the optimal spacing based on room dimensions, ceiling height, and beam angle.
How to Use
- Enter room length, width, and ceiling height (in feet).
- Set the beam angle of your recessed lights (typical 60°).
- Choose desired brightness (foot‑candles) based on room type.
- Enter lumens per light from your fixture specification.
- Click “Calculate” to see number of lights needed, spacing, and beam coverage.
Example
Scenario: 15 ft x 12 ft living room, 9 ft ceiling, 60° beam, 30 fc, 800‑lumen LEDs.
Calculation: Area = 180 ft² → total lumens = 180 × 30 = 5400 lm → lights = ceil(5400/800) = 7. Beam coverage diameter = 2 × 9 × tan(30°) ≈ 10.4 ft. Spacing ≈ 0.7 × coverage = 7.3 ft. Keep 2 ft from walls.
Why Use a Recessed Lighting Calculator?
Proper recessed lighting layout ensures even illumination, avoids dark spots, and prevents glare. This calculator uses both the lumen method (to determine how many lights) and beam geometry (to recommend spacing). Simply adjust the beam angle to match your fixtures — narrow beams need closer spacing.
Whether you’re planning a kitchen, living room, or office, this tool gives you a professional starting point. Always consider local building codes and consult an electrician for final installation.