Recessed Lighting Calculator
Planning a recessed lighting layout? Enter your room dimensions and desired brightness, and this calculator tells you exactly how many lights to install and how far apart to space them. No more guessing whether your room will be too dim or too bright.
The core formula is:
Number of lights = (Room sq ft x Foot-candles) / Lumens per light
Recommended Foot-Candle Levels
| Room Type | Foot-Candles |
|---|---|
| Hallways, Stairs | 15-20 |
| Living Room, Bedroom | 20-30 |
| Kitchen (general) | 30-40 |
| Kitchen (task areas) | 50-70 |
| Office, Workshop | 50-70 |
| Bathroom | 40-50 |
Spacing Guidelines
- General rule: Space lights evenly in a grid pattern
- Wall offset: Place the first row at half the spacing distance from the wall
- 4" fixtures: Better for focused task lighting, closer spacing
- 6" fixtures: Better for general illumination, wider spread
For example, a 15x12 ft kitchen (180 sq ft) at 40 foot-candles with 800-lumen lights needs 9 lights spaced about 4.5 feet apart, with the first row about 2.2 feet from the wall.