How Many LED Lights Per Square Foot? Commercial Lighting Calculator
Calculate how many LED fixtures you need per square foot for warehouses, offices, retail, parking lots, and more. Includes foot-candle requirements by space type.
One of the most common questions contractors and facility managers ask: "How many LED lights do I need for my space?" The answer depends on the space type, ceiling height, desired light level, and fixture output.
Quick Reference: LED Fixtures Per Square Foot
| Space Type | Required FC | Ceiling Height | Fixture | Spacing | Coverage |
|---|---|---|---|---|---|
| Warehouse (general) | 30 FC | 20-30 ft | 150W UFO High Bay | 20x20 ft | 400 sq ft each |
| Warehouse (detailed) | 50 FC | 20-30 ft | 200W UFO High Bay | 15x15 ft | 225 sq ft each |
| Manufacturing | 50 FC | 15-25 ft | 200W High Bay | 16x16 ft | 256 sq ft each |
| Office | 40 FC | 9-10 ft | 50W 2x4 Troffer | 8x8 ft | 64 sq ft each |
| Retail | 50-75 FC | 10-14 ft | 50W Panel Light | 6x8 ft | 48 sq ft each |
| Parking lot | 2-5 FC | 20-30 ft pole | 150W Area Light | 60x60 ft | 3,600 sq ft each |
| Parking garage | 10 FC | 8-10 ft | 40W Vapor Tight | 20x20 ft | 400 sq ft each |
| School classroom | 40 FC | 9-10 ft | 40W 2x4 Troffer | 8x8 ft | 64 sq ft each |
| Gym/recreation | 50 FC | 20-30 ft | 240W High Bay | 20x20 ft | 400 sq ft each |
Step-by-Step Calculation
Formula
Number of fixtures = (Area × Required FC) ÷ (Lumens per fixture × CU × LLF)Where:
- Area = square footage of the space
- Required FC = foot-candles needed (see table above)
- Lumens per fixture = from product spec sheet
- CU = Coefficient of Utilization (typically 0.6-0.8)
- LLF = Light Loss Factor (typically 0.85 for LED)
Example: 20,000 sq ft Warehouse
- Required: 30 foot-candles
- Using: Auvolar UFO High Bay 150W (22,500 lumens)
- CU: 0.7 (typical for warehouse)
- LLF: 0.85
At $89 each = $4,005 total fixture cost. With DLC rebates of $50/fixture = net cost $1,755.
Example: 50,000 sq ft Parking Lot
- Required: 3 foot-candles (average)
- Using: Auvolar OT Series 150W Area Light (22,000 lumens)
- CU: 0.45 (outdoor, wider distribution)
- LLF: 0.85
IES Foot-Candle Requirements by Space Type
These are recommended levels from the Illuminating Engineering Society (IES):
Industrial
- Warehouse (general storage): 20-30 FC
- Warehouse (detailed tasks): 50 FC
- Manufacturing (rough work): 30 FC
- Manufacturing (fine work): 50-100 FC
- Loading docks: 20-30 FC
- Cold storage: 20-30 FC
Commercial
- Office (general): 30-50 FC
- Office (task lighting): 50-75 FC
- Retail (general): 50 FC
- Retail (merchandise): 75-100 FC
- Restaurant (dining): 10-20 FC
- Restaurant (kitchen): 50-75 FC
Institutional
- Classroom: 40-50 FC
- Library: 50 FC
- Hospital (general): 30 FC
- Hospital (examination): 75-100 FC
- Church: 20-30 FC (worship), 50 FC (reading)
Outdoor
- Parking lot: 1-5 FC
- Parking garage: 5-10 FC
- Walkway: 1-2 FC
- Building entrance: 5-10 FC
- Sports field: 30-100 FC
Free Lighting Design from Auvolar
Don't want to calculate manually? Auvolar offers free photometric lighting design for any project. Send us your floor plan and we'll create a professional layout with:
- Exact fixture count and placement
- Foot-candle calculations on a grid
- Uniformity ratios
- Energy code compliance verification
- 3D visualization
Contact: sales@auvolar.com or (626) 342-8856 or use our online tool at auvolar.com/tools/photometric-request.
Need Help With Your Lighting Project?
Auvolar provides free lighting design, photometric layouts, and rebate assistance for commercial projects.