Lighting Design Calculator
Calculate the number of light fixtures needed using the lumen method: N = (E × A) / (F × UF × MF).
Inputs
lux
m²
lm
m
Results
Fixtures Needed
21 fixtures
Actual Illuminance
504 lux
Total Lumens105,000 lm
Lighting Power Density0.98 W/ft²
How to Use This Calculator
- Enter the Target Illuminance in lux: office work ≈ 500 lux, warehouse ≈ 200 lux, precision tasks/labs ≈ 750–1000 lux.
- Enter the Room Area in m² and the mounting height above the work plane in meters.
- Enter the Lumens per Fixture from the manufacturer's datasheet (initial lumens, not depreciated).
- Set the Utilization Factor (0.4–0.7) based on room shape and surface reflectances — use the fixture's photometric data for accuracy.
- Set the Maintenance Factor (0.6–0.8): clean environments ≈ 0.8, dusty or industrial ≈ 0.6.
- Read the number of Fixtures Needed and the Actual Illuminance — adjust fixture layout to achieve target lux while staying within energy code limits (Lighting Power Density in W/ft²).
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