Example Data Table
| Court Type |
Length |
Width |
Target Lux |
Fixture Lumens |
CU |
LLF |
| Training court |
28 m |
15 m |
300 |
26000 |
0.70 |
0.80 |
| Recreation court |
28 m |
15 m |
500 |
32000 |
0.72 |
0.82 |
| Competitive court |
28 m |
15 m |
750 |
40000 |
0.75 |
0.85 |
Formula Used
Court area: Area = length × width
Delivered lumens: Delivered lumens = target lux × area
Adjusted lumens: Adjusted lumens = delivered lumens ÷ (CU × LLF)
Fixture count: Fixtures = adjusted lumens ÷ lumens per fixture
Actual lux: Actual lux = fixtures × fixture lumens × CU × LLF ÷ area
Spacing limit: Maximum spacing = spacing criterion × mounting height above work plane
Annual energy: kWh = total watts × hours per day × days per year ÷ 1000
Annual cost: Cost = annual kWh × energy rate
How to Use This Calculator
Enter the indoor court length and width in meters. Add the target lux level for your use case. Enter lumens, watts, CU, and LLF from the fixture data sheet. Add mounting height and spacing criterion to review layout quality. Then enter operating hours, energy rate, and cost details. Press calculate to see fixture count, layout, lux, spacing, energy use, annual cost, savings, and payback.
Planning Indoor Court Lighting
Basketball uses fast movement, high passes, and quick visual decisions. A court needs balanced light across playing zones, sidelines, benches, and scoring tables. Poor light makes the ball harder to track. It can also create shadow patches under players. This calculator turns court dimensions and fixture data into practical lighting numbers.
What the Numbers Mean
Illuminance is measured in lux. It describes how much useful light reaches the floor. Fixture lumens describe how much light the fitting produces. The coefficient of utilization estimates how much of that light reaches the court. The light loss factor allows for dirt, aging, driver loss, and lens reduction. These two factors make the calculation more realistic than a simple lumen total.
Fixture Layout Considerations
Indoor courts usually need uniform light, not only a high average. A design may meet the target lux, but still feel uneven if fixtures are spaced too far apart. The spacing criterion compares fixture spacing with mounting height above the playing plane. When spacing is too wide, dark bands and glare risks increase. The row and column suggestion gives a starting layout for a lighting plan.
Energy and Cost Review
The calculator also estimates connected watts, annual energy use, annual cost, and simple savings against an existing system. These values help compare LED replacements, new installations, and different lumen packages. Higher efficiency fixtures may cost more at first. They can still lower yearly operating cost, especially in schools, gyms, clubs, and training facilities with long daily use.
Useful Design Notes
For recreational basketball, many owners choose moderate lux levels. For league play, targets rise because speed and spectator viewing matter more. Light should also reach vertical surfaces, backboards, and rim areas. Clean lenses and planned relamping protect performance over time. The calculator includes maintenance factors so the design does not depend on perfect new fixtures.
How to Use Results
Treat the output as an early design guide. Final lighting should consider ceiling structure, wall reflectance, fixture optics, glare control, emergency lighting, switching zones, and local electrical rules. For competitive play or televised events, stricter standards may apply. Always confirm the final plan with a qualified lighting designer or electrical professional before purchasing fixtures or starting installation.
FAQs
What lux level is good for indoor basketball?
Recreational courts often use moderate lux levels. Competitive courts need higher levels. The correct target depends on play speed, viewing needs, ceiling height, and local requirements.
What is CU in lighting calculation?
CU means coefficient of utilization. It estimates how much fixture light reaches the court surface after fixture optics, room shape, and surface reflection are considered.
What is LLF?
LLF means light loss factor. It accounts for lumen depreciation, dirt, lens aging, driver losses, and maintenance conditions over the lighting system life.
Why does fixture spacing matter?
Wide spacing may create dark zones. It can also reduce uniformity. Good spacing helps the ball, players, lines, and rim stay visible across the court.
Does higher lumens always mean better lighting?
No. Optics, mounting height, glare control, beam spread, CU, and LLF also matter. A well-designed layout is better than a high lumen count alone.
Can this calculator estimate energy cost?
Yes. It multiplies connected watts by operating hours and days. Then it applies your energy rate to estimate yearly lighting cost.
Can I use feet instead of meters?
This version uses meters for length, width, and mounting height. Convert feet to meters first. One foot equals about 0.3048 meters.
Is this enough for final court design?
No. Use it for planning only. Final design should review glare, emergency lighting, controls, wiring, local code, and manufacturer photometric files.