Example Data Table
| Space Type |
Length |
Width |
Height |
Target Lux |
Fixture Lumens |
Fixture Watts |
| Small workshop |
50 ft |
30 ft |
14 ft |
300 |
15000 |
100 |
| Warehouse bay |
80 ft |
45 ft |
16 ft |
300 |
18000 |
120 |
| Indoor court |
95 ft |
55 ft |
18 ft |
500 |
24000 |
160 |
Formula Used
Area: A = length × width
Mounting height: Hm = ceiling height − workplane height
Required lumens: Lr = area × target lux
Effective lumens: Le = fixture lumens × utilization factor × maintenance factor
Fixture count: N = ceiling(Lr ÷ Le)
Average lux: E = total delivered lumens ÷ area
Total watts: Wt = fixture count × watts per fixture
Energy: kWh = Wt ÷ 1000 × hours per day × days per year
Current: I = watts ÷ (voltage × power factor)
Beam diameter: D = 2 × mounting height × tan(beam angle ÷ 2)
How to Use This Calculator
Enter the room length, width, ceiling height, and workplane height.
Choose a target lux level for the task area.
Add the rated lumens and watts for one low bay fixture.
Enter utilization and maintenance factors as percentages.
Add beam angle and spacing ratio for layout checking.
Enter operating hours, days, power rate, voltage, and power factor.
Press calculate. Review fixture count, spacing, power, cost, and savings.
Low Bay LED Lighting Planning
Low bay lighting is used where the mounting height is modest. The goal is even light at the task plane. A good layout starts with room size, target lux, fixture output, and light losses. This calculator turns those values into fixture count, spacing, load, and energy cost. It helps you compare practical options before buying equipment.
Why Lux Matters
Lux measures useful light on a surface. It is lumens per square meter. A warehouse aisle, gym, shop, or production area may need different values. Higher lux gives stronger visibility, but it can also raise wattage. The best target balances safety, comfort, and operating cost.
Fixture Count and Losses
Catalog lumens are not the same as maintained lumens. Room surfaces absorb light. Dirt, aging, lens haze, and heat reduce output. The utilization factor estimates how much light reaches the work area. The maintenance factor covers future losses. Multiplying both factors gives a realistic design value.
Spacing and Beam Spread
Low bay fixtures must be placed close enough for uniform light. Wide spacing can create dark bands. Very tight spacing can waste light and money. The mounting height and spacing ratio set a maximum recommended distance between fixtures. Beam angle also matters. A wider beam covers more floor area. A narrow beam can give stronger light directly below each fixture.
Power and Cost Review
After the fixture count is known, power is easy to check. Total watts equal fixture count times watts per fixture. Yearly energy uses hours per day and working days per year. The calculator also estimates current from voltage and power factor. This helps with circuit planning.
Better Design Decisions
Use the result as a planning estimate. Then compare it with site conditions. Check ceiling obstructions, racks, beams, doorways, dust, glare, and emergency lighting rules. Test a sample fixture if the project is large. A final lighting plan may need photometric files. Still, this tool gives a strong first layout for many low bay spaces.
For best results, enter real measured dimensions. Use manufacturer lumen data, not marketing claims. Update the energy rate from your bill. Save results for quotes. Compare two or three layouts before choosing the final fixture count and spacing pattern.
FAQs
What is a low bay LED light?
It is a fixture used for lower ceiling spaces. It spreads light across workshops, storage areas, shops, gyms, and smaller warehouse zones.
What target lux should I enter?
Use the light level needed for the task. Storage areas need less light. Detailed work, inspection, and sports areas usually need more light.
Why use utilization factor?
It estimates how much fixture light reaches the working surface. Walls, ceiling, fixture shape, and room geometry all affect this value.
Why use maintenance factor?
It accounts for dirt, aging, lens losses, and gradual lumen depreciation. It keeps the lighting plan realistic over time.
What does spacing ratio mean?
It compares fixture spacing with mounting height. A lower ratio usually improves uniformity. A higher ratio may create darker zones.
Can this replace a photometric plan?
No. It gives a strong estimate. Complex sites should still use fixture photometric files and a professional lighting layout.
Why is beam angle included?
Beam angle estimates floor coverage from each fixture. Wide beams cover more area. Narrow beams focus light more strongly below.
How is yearly cost calculated?
The calculator multiplies total kilowatts by yearly operating hours and energy rate. This gives an estimated annual running cost.