Estimate tennis court light fixtures, maintained brightness, total lumens, power use, and monthly energy cost from simple lighting inputs.
Advanced options
Table of contents
How to use our Tennis Court Lighting Calculator
- Enter the Number of courts, then choose the Area to light. Use the full 120 ft by 60 ft option for most planning estimates, or choose Custom size if your lighted area is different.
- Pick the Target court brightness, then enter Lumens per fixture and Watts per fixture from the fixture spec sheet.
- Open Advanced options if you want to change Light left after aging and dirt, Light that reaches the court, Use time, Electric price, or Number display.
- Select Calculate and compare Fixtures needed with Estimated maintained brightness. The brightness should meet or beat your target because the fixture count is rounded up.
- Sanity-check the result: if Fixtures needed seems very high, recheck area, target lux, fixture lumens, and the two percent loss inputs before using the estimate for budgeting.
Definitions
Lumens per fixture: The rated visible light output from one light fixture before light loss, aiming loss, dirt, or aging are applied.
Lux: A measure of light reaching a surface. One lux means one lumen spread over one square meter.
Foot-candle: Another surface brightness unit often used in the US. One foot-candle equals 10.7639104167 lux.
Target court brightness: The planned average maintained brightness on the court surface, entered in lux.
Light left after aging and dirt: A percent factor for lumen loss over time from aging, dirt, and cleaning conditions.
Light that reaches the court: A percent factor for rated fixture light that actually lands on the lighted court area.
Estimated maintained brightness: The average brightness after the calculator applies loss factors and rounds the fixture count up to whole fixtures.
kWh: Kilowatt-hour, the energy used by running 1 kilowatt of power for 1 hour.
Common mistakes and quick fixes
Mistake: Using Number of courts for total players or total poles instead of courts.
Fix: Enter the count of courts that will receive the same lighting setup.
Mistake: Choosing Area to light as the playing lines only when you really need the runoff space lit too.
Fix: Use the full 120 ft by 60 ft preset unless you are intentionally estimating only the marked court lines.
Mistake: Entering Lumens per fixture as the total for all fixtures.
Fix: Enter the rated lumens for one fixture only, such as 30000 for one 30000 lm light.
Mistake: Typing Watts per fixture from the LED chip rating instead of the full fixture input watts.
Fix: Use the fixture input power from the spec sheet so Total power while lights are on is realistic.
Mistake: Setting Light left after aging and dirt or Light that reaches the court to 100 percent by default.
Fix: Use realistic loss factors unless you have a photometric plan that supports a different value.
Mistake: Treating Estimated maintained brightness as proof that the court will be evenly lit.
Fix: Use the Design note and get a lighting layout checked for glare, shadows, pole placement, and uniformity.
Limitations & Key Assumptions / Boundary Conditions
- This is a planning estimate for average light level. It is not a photometric lighting plan.
- The calculator cannot verify uniformity, glare control, pole height, pole location, aiming, shadows, spill light, permits, or neighbor impact.
- Preset areas use 120 ft by 60 ft for a full single-court lighting area and 78 ft by 36 ft for the playing lines only.
- The result assumes every fixture has the same Lumens per fixture and Watts per fixture.
- The two percent loss inputs are broad planning factors. Real values depend on fixture optics, mounting height, dirt, weather, aiming, and maintenance.
- Monthly energy cost is for electricity only. It excludes equipment cost, installation, demand charges, maintenance, controls, and utility fees.
- Rounding up to whole fixtures can make Estimated maintained brightness higher than the target, especially with very bright fixtures or small custom areas.
Methodology
How the estimate is calculated
The calculator first turns the selected court area into square feet, then into square meters. Lux is lumens per square meter, so the target lux is multiplied by area and court count. The result is divided by the combined light loss factor because not every rated lumen reaches the court and lighting gets dimmer over time.
area_ft2 = length_ft * width_ft
area_m2 = area_ft2 * 0.09290304
combined_factor = (Light left after aging and dirt / 100) * (Light that reaches the court / 100)
Total fixture lumens needed = Target court brightness * area_m2 * Number of courts / combined_factor
Fixtures come in whole units, so the calculator rounds up the needed lumens divided by Lumens per fixture.
Fixtures needed = ceiling(Total fixture lumens needed / Lumens per fixture)
After rounding, it recalculates the maintained brightness from the installed fixture lumens. It also converts lux to foot-candles.
Estimated maintained brightness in lux = Fixtures needed * Lumens per fixture * combined_factor / (area_m2 * Number of courts)
Estimated maintained brightness in foot-candles = Estimated maintained brightness in lux / 10.7639104167
Power and cost use the rounded fixture count, so cost matches the number of fixtures shown.
Total power while lights are on = Fixtures needed * Watts per fixture / 1000
Estimated energy use each month = Total power while lights are on * Use time
Estimated energy cost each month = Estimated energy use each month * Electric price
Mini example
For 1 full court at 120 ft by 60 ft, the area is 7200 square feet, or 668.901888 square meters. With a 300 lux target, 80 percent light left after aging and dirt, and 70 percent light reaching the court, the combined factor is 0.56. Needed fixture lumens are about 358340 lm. With 30000 lm fixtures, the calculator rounds up to 12 fixtures. Those 12 fixtures give about 301.39 lux, or about 28.00 foot-candles. At 400 W each for 60 hours per month and $0.18 per kWh, the monthly energy cost is $51.84.