Formula Used
The calculator first finds the room area. If feet are selected, the area is converted to square meters for lux calculations.
- Area = Length × Width
- Mounting Height Above Work Plane = Mounting Height − Work Plane Height
- Usable Lumens = Fixture Lumens × Utilization Factor × Light Loss Factor
- Required Fixtures = Target Lux × Area ÷ Usable Lumens
- Beam Diameter = 2 × Mounting Height Above Work Plane × tan(Beam Angle ÷ 2)
- Maximum Beam Spacing = Beam Diameter × Beam Overlap Factor
- Maximum SHR Spacing = Mounting Height Above Work Plane × Spacing Criterion
- Average Lux = Installed Fixtures × Usable Lumens ÷ Area
How To Use This Calculator
- Enter the room length and width.
- Select meters or feet.
- Enter mounting height and work plane height.
- Add target lux for the task area.
- Enter fixture lumens, watts, CU, and LLF.
- Add beam angle and spacing criterion.
- Use zero manual fixtures for automatic sizing.
- Press calculate to see the layout above the form.
- Use CSV or PDF buttons to save the result.
Example Data Table
| Area Type | Room Size | Mounting Height | Target Lux | Fixture Lumens | Beam Angle |
|---|---|---|---|---|---|
| Warehouse storage | 60 m × 30 m | 9 m | 200 | 30000 | 90° |
| Assembly floor | 50 m × 25 m | 8 m | 500 | 36000 | 100° |
| Sports hall | 40 m × 22 m | 10 m | 400 | 40000 | 80° |
| Loading bay | 35 m × 18 m | 7 m | 300 | 24000 | 110° |
Advanced LED High Bay Spacing Guide
High bay lighting works best when fixture spacing, mounting height, beam angle, and lumen output are balanced. A warehouse can look bright under one fixture and dim between rows. This calculator helps reduce that problem. It uses the lumen method and a spacing check. It also estimates the practical row and column layout.
Why Spacing Matters
Spacing controls uniformity. Wide spacing may save fixtures, but it can create shadows. Tight spacing improves balance, but it can raise power use and glare. The best plan normally keeps the center spacing below the allowed spacing-to-mounting-height ratio. Beam spread should also overlap at the work plane.
Planning Inputs
Start with room length and width. Then enter mounting height and work plane height. The difference is the mounting height above the task. Next, add target lux, fixture lumens, utilization factor, and light loss factor. These values estimate useful light after fixture, room, dirt, and aging losses. Add watts, operating hours, and energy cost when you want a running cost estimate.
Layout Review
The tool compares the lumen requirement with spacing limits. It searches for a row and column grid that fits the room shape. It reports center spacing, edge offsets, average lux, installed watts, annual energy, and estimated cost. If spacing is too wide, increase fixture count or choose a wider beam. If the average lux is too low, use more lumens or better utilization. If energy use is too high, compare efficient fixtures.
Advanced Use
High bay layouts are affected by aisles, racks, doors, cranes, and machines. The calculated grid is a starting point. Move fixtures around obstacles only after checking spacing again. Long narrow rooms need more columns than rows. Square rooms work best with balanced rows and columns. High ceilings may need narrow beams. Lower mounting heights may need wide beams or tighter fixture spacing.
Practical Notes
Use manufacturer photometric files for final design. Real projects may need glare checks, emergency lighting, rack shadows, skylight allowance, and local code review. Treat this calculator as a planning aid. It is useful for early estimates, bid checks, layout studies, and quick comparisons between high bay products. Always test a sample area when the surface finish is critical.
FAQs
What is high bay lighting spacing?
It is the distance between fixture centers. Good spacing gives better uniformity and avoids dark patches between fixtures.
What is the spacing criterion?
It is a multiplier applied to mounting height above the work plane. It gives a practical maximum spacing limit.
Why does beam angle matter?
A wider beam spreads light farther. A narrow beam concentrates light and may need closer fixture spacing.
What does CU mean?
CU means coefficient of utilization. It estimates how much fixture light reaches the useful working area.
What does LLF mean?
LLF means light loss factor. It accounts for dirt, aging, lens loss, and lumen depreciation over time.
Can I use feet with lux?
Yes. The calculator converts square feet to square meters internally before using the lux formula.
Why is the installed fixture count higher?
The grid may add fixtures to keep rows and columns balanced. It can also help satisfy spacing limits.
Is this enough for final design?
No. Use photometric software and manufacturer IES files for final plans, code checks, and glare review.