Lighting Lumen-Method Worksheet
Average-illuminance arithmetic using user-reviewed utilization and maintenance factors; not a uniformity or compliance result.
Average-illuminance arithmetic using user-reviewed utilization and maintenance factors; not a uniformity or compliance result.
No current calculation
Enter and review the parameters, then calculate. The fixed example below is not your current result.
Method and boundaries
Required emitted lumens = target lux × floor area / (UF × MF). Divide by lamp lumens × lamps per fixture and round upward. An illustrative rectangular grid may add fixtures; average lux uses the actual grid count. Spacing is geometric only, not a photometric recommendation. Enter supplier/application-specific UF and MF (0.001–1), and fixture watts. Room and fixture-plane heights are recorded for geometric context, not used to invent uniformity. Bounds: room length/width 0.01–1000 m; fixture height 0.01–100 m above floor and above working plane; working plane 0–99 m; target 0.01–100000 lux; lamp lumens 0.01–1000000; integer lamps 1–100; fixture watts 0.01–10000. Derived counts must be safely representable integers and all derived values must be positive and finite. No product certification or code verdict.
Fixed worked example — not a live result
Hypothetical example: 10 × 8 m, 500 lux target, 4000 lamp lumens, 1 lamp/fixture, UF 0.7, MF 0.8 => 18 minimum fixtures. A 4 × 5 grid installs 20 and estimates 560 average lux. These factors are assumptions, not verified fixture data.
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Worksheet version 2026-10-15. Verify source applicability and all omitted requirements before any real-world decision.
Next calculation, separate decision
Understand ideal offset geometry before consulting the bender chart. Each worksheet has different assumptions and does not approve a design.