Room Lighting Calculator
Find out exactly how many lumens and light fixtures your room needs based on size and room type.
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How Room Lighting Is Calculated
The standard method for residential and commercial lighting uses foot-candles (fc) — a measure of how much light falls on a surface. Required lumens = foot-candles × room area in square feet. For example, a 12×10 ft kitchen (120 sq ft) at 50 fc requires 6,000 lumens total.
Ceiling height also matters. Taller ceilings spread light over a larger area, reducing effective illuminance at floor level. A rough adjustment adds ~10% more lumens per foot of ceiling height above 8 ft.
Recommended foot-candle levels by room type:
| Room | Foot-Candles (fc) |
|---|---|
| Hallway | 10 fc |
| Bedroom | 15 fc |
| Living Room | 20 fc |
| Garage | 30 fc |
| Kitchen / Office | 50 fc |
| Bathroom | 70 fc |